Heres a neat trick, get a clear cup and a solo cup, cut holes in the bottom of both. Place the clear cup in the solo cup. The clear cup will allow u to see root development and overall soil moisture and the solo cup will shield those roots
For seedlings, i just make sure soil is nice and moist when i first sow them then dont water until i see the top get dry usually 5-7 days later. Once they on there second or third node u can start misting and apply very light foliar feed. I dont think u need to add any npk nutes to the soil until they are on node 3 or 4. Worm castings will do well for the first 4 nodes, then slowly bring in ur npk nutes (1/8-1/4 strength) if ur soil is kinda bare.
For starting seeds, i like the paper towel method, then put it in a zip lock and tack it to the wall. U want it to be vertical so the roots think they are digging “down” instead being on a flat surface where they think they are hitting a rock. Usually 24-48 hours i sow the seed with the cup 3/4 full, so the seed is just poking out and the root is ahoved in a hole. As the seed grows i fill the room around it until its done stretching (usually 72 hours after being sowed). I leave the first cotyledon leafs sticking about an 1/8" above the soil, that gives the plant a good support stem to start its growth.
At node 4 is when i start bending it over or topping it