How to go upwind
First of all you need enough wind to be able to lean against the kite and don't have to move it up and down.
If you use a directional you run upwind better by using the fins. With your feet you steer the board and then you have to straighten your back foot more so the board will run more upwind.
In general it is important to turn your head and body into the direction your heading. Look at a point where you want to go upwind to. This way you will instantly turn your body.
If you use a twintip, you work more with the edge. So if you have enough power in the kite you always edge hard and if a gust comes you even edge harder. Important is that you don't get too fast, otherwise you can't hold the edge and the kite will pull you downwind. So always keep control of the kite and speed with your edge. It pulls hard, edge it harder, it pulls softer, edge less.
tThe board is NOT a shovel! Many times beginners tend to push both legs in front hard either cause they are tired or cause they think that will get them upwind. The key is, when powered up, put the kite around 10 or 11 oclock and, with a MODERATE board speed, you have to begin to play with the ANGLE of the board. The board is a KNIFE! even if you feel like you might be going downwind a bit you need to sometimes point your board a litttttle bit more towards the kite, that is, a bit less into the wind, so the the EDGE of the board is SLICING rather than PUSHING the water. I find that if you are powered and can park the kite around 10 or 11 oclock you can really experiment with foot pressure and angle of the board easier. Of course, if you are powered and comfy its even better in the fixed loop so that you arent changing the angle of attack of your kite constantly with tiny movements in the chicken loop. You want to keep "all things constant" EXCEPT the board angle so you can really find the right "slicing angle" to get upwind. This will also result in LESS spray into your eyes once you find the "sweet angle"
Remember that this sweet angle CHANGES depending on how powered you are and where the kite is in the window.