Nothing is really "perfect" in SEO, different strategies work for different people of different sizes
to be honest, you get the hang of it after around 10 videos. my best tip is to write a sentence in the description which usually describes your video. mix in tags to get it in search without breaking SEO rules so that way theres not too many in the description
Example: if your tags are cake, chocolate cake, etc, narrow it down further to what cake your making because often smaller channels have a hard time hitting "one word keytags". avoid too high of search because if someone searches up "cake" your video will most likely not come up. However, your video will come up if you have "strawberry chocolate seven layered cake' etc. aim for tags to have at least 2 - 3 words when your small.
now, lets make the sentence:
"in today's video, i made a strawberry chocolate seven layered cake. there were strawberries with chocolate on the cake and in the video i also showed tips and tricks to make a chocolate cake.
add those words as your tags as an example
hope this helped