If you can't do it, you spend a lot of your day walking up the beach.   Commonly known as "The Walk Of Shame".

At my local surfsport, I spend the day doing triangles.   I surf downwind a kilometer or two, then need to work back upwind in two tacks to get back and do it all again!    

For me, the trick has always been things like looing upwind.  Sounds trivial, but makes a huge difference - fix your sight on where you're heading, and it's a pretty good start.   Twist your body, so your whole posture is about going upwind.   You also need to be reasonably powered up, so that you can drive it through your feet to grind the board upwind.    The speed also helps your board keep traction in the water.  If you're hitting swells, you might bend your knees to absorb them, so you don't lose all your speed.

Superlizard suggests:

I do'nt think that looking where you want to go is the key... it may help, but it's really your foot work and edging that makes you go one way or the other. I can go upwind by looking backwards... what i found made a HUGE impact when learning upwind, is:

1 - twist your back foot slightly backards - oposite direction of travel - this will help put more pressure and edge on the back of the board... kind of like if you are doing twist dance...
2 - keep your front leg straight - that's a proper stance - unless you wanna be called a pooman... although this is just a general remark, the first point is what will help with upwind
3 - it's likely that a type of kite you have may be further making it harder... when i used to do landboarding, i had a kite that just couldn't get me going upwind...

djdojo collected comments from previous topics:
Any modern board that's the right size and not absolutely wake-dedicated is fine (the custom is not helping due to lots of rocker and 132 is small for that style of board, but you should be able to get it unless you're 100kg). upwind, as with light wind, is all about technique. of course dedicated boards will go better in the right hands/feet, but my experience is that a small gain in technique will yield more satisfying results than dropping a grand on a new toy. here are some tips. (i raced boats and sailboards for many years before kiting so there's some sailing lingo in here.)

A really light touch on the bar and a delicate balance between front and rear foot pressure will let you respond quickly to slight changes in wind speed and direction.

If you hit a lift (wind shifts so you can point higher) let the bar out a fraction and edge just a little harder to steer upwind further.

If you hit a knock/header (wind shifts so you can't point as high) flatten out your board to maintain speed as you bear just as far downwind as you need to keep the kite powered up.

In a gust let the bar out a bit to let the kite fly further forwards and load up your back heel a bit more to point a little higher.

In a lull shift some load to your front foot and flatten the board a bit to maintain speed. if you need to pull the bar in briefly to keep the kite powered as you adjust course, be prepared to let it out again quickly to prevent stalling.

Look upwind. your head leads a twist through your torso and this helps keep things loaded up automatically to point high.

Again, a delicate and responsive sensitivity to shifts in wind speed and direction and water conditions (bend knees over chop to keep up your speed and edge and not bounce downwind) lets you take full advantage of the conditions to find the sweet balance of speed and angle.

Beersy reckons:

I did say slightly bent, not tucked right up. No pooman stance. I use this technique and it gets me upwind, also easier on the legs. I do agree with you that it isn't the correct stance and only do it when I want to get upwind quick, such as on shore wind. But does work imo

Hayman chipped in:

Use your trim strap by pulling it in a couple of inches which will sheet the kite out, making it fly further around to the edge of the wind window; thus increasing the angle of attack upwind.

keep ya kite low, which will help you hold a solid edge to drive upwind.

fly with one hand once ya got your speed up, this will rotate ya hips around, pointing the nose of the board upwind more.

The majority of the power should be coming through ya front lines into ya harness. There should be barely any tension in ya steering lines once youve got your speed up. If there is alot of tension in ya steering lines, its means ya got the bar to close to you, which is choking the kite and resulting in you going downwind..

Dutchy1985 said:

One thing which I was told that REALLY helped was don't try too hard to go upwind, if you try to lean too much/point too high, you will just slide out and go downwind.

D_Meredith79 :

Make sure you are pushing your weight through your heel in your back foot while pulling up (towards your head) with the toes of your front foot. It was stated earlier that you should straighten your front leg, it should be pretty much straight, but NEVER lock your knee, that's how I torn my Medial Miniscus Not fun. Keep your front leg only slightly bent and squat more onto your back leg ensuring that you are leaning back against the pull of the kite and slightly twist your body upwind.

Getting the right angle of lean and remembering the feet at the same time is the key

timomo:

I think the description for snowboarding may help to explain what some are hinting at, when you look somewhere up wind your shoulders rotate, which then rotate your hips which will turn you into the wind. another way to emphasise this is to point to and look where they want to go, which is how beginners are told to initiate a turn in snow boarding (again rotating the body through the hips)

A couple of video's popped up: