I just did a search for you - typed in Topknot and found many threads...but you said you have been reading so I can try to offer a tiny bit of help...
with my girls - I started with PetEdge Bows - I bought a BUNCH (pack of 50) and they have pretty strong elastic and stay in for hours - On Cheri I always have to twist the band 3-4 times - I really love their bows for everyday use.
there are LATEX bands you can get anywhere that work just as well as the bows - It's just a matter of practicing - don't make it too tight that they hurt and don't make it so loose that it falls out.
I started with small amounts of hair to get the girls used to bows and nothing big on her head - she'll know it's there and want it out....so....little bows to start
GOOD luck !