Landings, the non-optional part of flying.
I had trouble mainly because of the weather, crosswinds, thermals, rain, etc etc.
BUT now I feel well equiped.
I agree with Tomo I use the arm on the armrest to guide myself, I look down the run way to get a sense of hight.
But all in all it just came together. You just have to relax. (Easier said than done)
Oh yeah by the way, you'll nail your landings until solo, about the second or third one you seem to completely forget how to do it again :)
Fly safe
Bec