New Grower Tips

First time grower here and just wanted to see if you guys would do anything different for your plants to help them grow. So today makes day 18 since my seedling have sprouted and been under 18/6 light schedule. On day 14 the plants were transferred. They get watered with 6.5-7 ph balance water every 4-5 days. No nutrients added yet. However most of the knowledge I have it from watching YouTube day and night. However, I’d like to get opinions of anything different that would make the growing process easier since this is my first grow or even so common tips that a beginner should know. Any tips for the future... anything, all advice big or small is helpful.