After you defeat Ganondorf there r no more missions to complete other than collecting heart pieces and golden bugs but if u want u can reenter Hyrule Castle and defeat Ganondorf again

i go to fishing hole and fish, i have all lures i think, (frog, sinking, swimmer, spinner, and popper.) and just catch fish, also use your fishing pole, u can use bee larva too, if u fish with it at fishing hole, u can get an emty bottle.

after u beat ganondorf theres bassically nothing u have to do. i usually just try to find
60 poes or get the great faeries tears(its very hard though and i have been trying to get
them for a long time.) and sometimes if i didnt already do it i go find all of the golden
bugs.