I have found that it is a ~lot~ easier to get meds into a sweet, drowsy kitty than one who is hyped up after a rigorous play session! *grin*
As for hints, you watched the vet/vet tech when they applied the ointment in the office, right? So you know the mechanics of how to do it - the problem is doing it fast enough so that you achieve actually putting the medicine where you want it to go before kitty wises up and is on to you. Just reach in there, pull the lower lid down as you can, and get the ointment on the inside of the rim as best you can. Other than that, the only advise I can give you is that it might help to have a second pair of hands to assist you. Even a 13 week kitten can be quite a bit more than a handful, especially if you also have to use your hands to medicate!
The antibiotic drops are actually easier - I don't envy you the eye ointment at all! You have to be careful about how fast you squirt the stuff in though - it's easy to choke kitty going in from the front. Again, a second pair of hands might be helpful, but take your right hand (if you are right-handed) and using your thumb on one side and your forefinger on the other side, come up from underneath the chin and gently squeeze the corners of kitty's mouth to make it open. Once you've done that, then you insert the dropper into the SIDE of the mouth - not into the mouth - between the teeth and the "cheek" (do cats have cheeks???) and then gently squirt in the drops, making sure kitty is swallowing and not allowing it to pool up. If you see it pooling up in there or running out of the side, stop and try again after kitty swallows.
I sincerely hope this helps - please let us know how you get along.