I've been starting seeds indoors for over 5 years, so this is my first official "indoor seed starter" thread!
I have a modified DIY gro station, using this YouTube video as a starter. Modifications? A 4-bulb shop light, longer legs, sturdier chains on the shop light and taping half an emergency blanket (99 cent pocket-sized packaged) on the suspending PVC pipe and letting it drop down the backside, to reflect light back onto the seedlings.
https://youtu.be/ifimJYiPw50
This accommodates: 2 1/2 10-20 trays of newly-sprouted seedlings (vertically to the shop light) and 5 1020 trays of seedlings being grown out (perpendicular to the shop light).
This year, so far, I have started/sprouted/ am growing out -
Brussels sprouts
French marigolds
Hot peppers (both jalapenos and ornamental varieties)
Tomatoes
Monday, I will start nasturtiums
Later:
yellow crookneck squash
pickling cucumbers (two varieties)