Maybe I can return the favor of your advice about my tired arms.
With Roger's help I have found a method for going upwind that sounds goofy but works well when I'm not planing - I might need 3 or 4 knots more to get going. I used to try sinking the windward rail and using the nose to scoop upwind but that hardly ever worked.
What I do now is to point the board about 30 degrees upwind, stand close to the mast and keep the board flat side to side and front to back. The part that seems weird is how I sheet the sail in. I used to think that you sheeted in hard and leaned the sail back. Now I barely sheet in at all. I tried taking both hands off the boom but even that is oversheeting. So, I take my back hand off but keep my front hand on the boom. I pull gently with my front hand to keep the sail from oversheeting because it will just from harness pressure alone.
In summary point your board about 30 degrees upwind and keep it flat. Stand by the mast and sheet in very lightly. Try it when not planing.
When planing if you're not too powered up try pointing more upwind with the board flat but don't sheet in too hard. If you're really smoking, lean that sucker (the sail) back, sheet in fully and push on the fin with your back foot. Again point way upwind.
Let know me if this helps.