Hi There,
I am possibly the last person who should gives tips in regards to upwind-ability but what i have found in other forums is to keep your kite somewhere between 45 and 90 degrees, do longer runs out, rather go slowly out to sea than either flying out and loosing ground or putting to much backfoot pressure and stalling the kite, move your back foot forward just in front of your outer fins (level the board out) and if you are natural go right switch foot every couple of waves (really gain a sh1t load of ground).
Another thing to add to going slowly out is to pull just enough of the bar in to maintain speed so that the kite fly's more forward. Another thing is to fly the kite just enough so that it moves forward in the window but without pulling you down wind.
The other option is just to do downwinders - 
which is my preference (to the extent of doing a 5km walk back to the start).
Hope this helps, I am till testing some of these theories.
Cheers
Rich
While working upwind move your back foot forward to about 30cm (or less) from your front foot.
You might also need to move your front forward a little if you're in a full-on surf stance. Maybe stand a little more upright as well.
You can do this for both toe and heelside. It's also a good way to rest the back leg if you've been hitting it hard on toe-side.
Do all the kite trimming stuff that other people have mentioned.
I rarely do downwinders. My thing is to ride upwind about 6km from my launch point then hit the reefs and sand bars all the way back. It takes about 45 minutes to get upwind and is a nice scenic little sail. On the way back I might spend 10 minutes or so staying at each break then move on to the next for a 2 hour round trip.
You should be able to go upwind much better without straps because you can move your feet forward and out onto the rail. Don't try to ride toe side when going upwind either. I learnt to ride properly on flat water before trying to ride in the surf. You will learn much faster without the waves. I mean if you can't ride your board upwind, you aren't going to be able to have much fun or utilise the fact you are riding a surfboard.
Lots of good advice already given, so just practice, a strapless surfboard is the best choice for going upwind.
Getting upwind on a surfboard should be fair easy - you have so much more bite with the big fins and large surface area.
I switched to a smaller surfboard - a North Freestyle Fish - and had some trouble getting upwind, and I think the problem was that I was losing my track everytime I hit some chop. Fixed the problem with some stiffer and thicker fins, along with being more careful to keep my sense of direction as I hit the chop.
On a larger board, its just a matter of bringing you heels a bit closer to the edge, and moving your feet a bit more forward on the board. I like to try and get my body as close to horizontal as possible, balancing myself by powering/depowering the kite, flying the kite in small figure 8s or Zs, and controlling my speed by changing the track slightly into or away from the wind. How you handle the chop is important, and if you are lying way back, you can ride the board over the chop edge-on, but you may need to turn the nose a little into the wind as you go over the chop - this will help the kite to keep you pressed down onto the board.
I haven't quite figured it out, but sometimes in light winds, its easier to ride the tail and get upwind.
After many months of riding strapless, I still cant quite get my gybe right. I can carve the board around just fine, continuing to ride toeside, but I can only do the foot switch successfully about half the time. I've also tried doing the foot switch before I carve around, and I can get that about half the time too.
Anyone got any tips on how to switch feet? What do you do with the kite as you switch?
Learn to ride switch in flat water first not so much toeside but heel side a must.
Gotta' say that I always ride natural stance on my surfboard-therefore always toe or heel going upwind depending upon where the wind is from-I NEVER switch to heel and find it just as easy to go upwind heel or toe-so don't agree with those that say you need to learn to switch to go effectively upwind-this segues into the ridiculous discussion on whether riding waves backside down the line sucks and everyone should be switching (ie as a windsurfer and NOT like a surfer)-not a debate for this thread and not worthy of any attention-it's all up to you.
Went out today in about 16-20 cross on and thought about this thread and took particular note of my feet etc. I always have my harness swiveled way around so the hook is off the down wind hip when pointing hard.
Toeside I tend to have my back foot so that the stringer on the board is about 1/5 of the way up my foot (measuring from my heel-so the bulk of my foot is on the windward side of the board-really driving the rail into the water and pointing the nose hard to windward-front foot is about even and used to keep the board on track-I tend to lean hard to windward to really drive the board against the kite and keep it powering upwind. Heelside similar-but the bulk of my back foot is over the windward side of the board-stringer now about 1/5 when measured from my toes-same deal with the front foot. I tend to sue a pretty wide stance to ensure I have as much rail in the water as possible-acts like a keel to drive you upwind.
Hope all that makes some sense and isn't too much crap-just works for me-naturally practice/time on the water will help you discover out what works best for you.
Select to expand quote
Only ride 2 kites a 9m or a 6m-I'm about 75-76kg on a 601 surfboard. Depends upon how much wind there is as to whether I'm powered or working the kite- where I'm at, usual winds about 14-18 knots.
So the comments and suggestions i have been receiving about keeping the board flat and letting the fins do the work are not correct ?
I must still bury that rail and turn the board upwind ?
Hey slave, do you paddle surf both goofy and natural so as you feel more masculine?.... or does that idea only apply to kiting?
Just thought i would post my solution to my problem with going/staying upwind on a strapless surfboard.
Locolas your tips are right on the mark i might add thanks.
Basically my mind set was wrong. Coming from a long surfing background with NO sailing experience, i assumed that if i was losing ground, i need more floatation, so i moved my front foot up just past the middle of the board and slid my backfoot right up to the middle (just like i would if i was tring to get through a flat section to make the reform on a wave) then flattening out the board for extra planability.
Even if you go slow and try to use the fins to direct, this method doesnt really work to well ! 
I now realise you dont need to move that back foot all the way up !
Basically i was over compenstating, i hope this helps anyone that comes from a surfing background to kiteing.
Thanks again to all that helped me with this topic i had an excellent session this weekend !Done my first complete round house and hacked a few right to the beach ! then straight back outto the next wave with no lose of ground !
it felt soooo good !
)-wait till you get a few barrels or some fins out the back airs-smiling ear to ear.
I tend to find moving my front foot around a bit tricky, would it not be easier to move the back foot forward when trying to go upwind.
And then compensate with just shifting your weight forwards and backwards.
Look at the guys like Felix and Tophat on their videos, they tend to put their back foot infront of the back grip / side fins.
But then again I suck at going upwind, so next time I'll try your method.
Cheers
Rich
staying up wind would have to a no brainer on a strapless s/board it easy
even in lite winds
One tip totally overlooked is to look where you're going! Sounds basic, but works.
If you're out the back, it's easy to get absorbed in watching the oncoming chop - try fixing your vision on a point on the horizon and head towards it - it makes a big difference in getting where you're going.
As a few crew have already said, heelside is essential for making serious ground upwind ... if you're struggling with your gybing, check this article out...
www.seabreeze.com.au/Articles/Kitesurfing/How-to-gybe-a-surfboard_2165971.aspx
Learning to gybe can take your kiting fun backwards for a few sessions, but I can assure you the rewards are well worth it.
