I feel silly telling people on a site of this caliber how to start seeds but youd be surprized at the veteran growers that have problems.
Tip 1
Do not use a fucking heat mat to start seeds!
I have seen more quality genetics cooked this way than I can tell you.

Cannabis is a weed and the seeds will start if viable in almost any condition, want me to prove it.
These are seeds I deemed un worthy that were blown out of my sifting pan on to rocks under my BBQ grill our average temps are like 50 currently!

So this is how I feel is the best way to start seeds.

Wash hands well with disinfectant soap

Place seeds in Rapid Rooters with the Point up and button end down.

Place in Dome
Leave alone till they sprout

Its really not more complex than that. The light from your flo is plenty energy to crack seeds.

I lived in Winnepeg and didn't use a heat mat to start seeds or root clones and thats the coldest place I hope anyone lives.

Ok so were clear no heating pads under seeds right?

This is not an insult to anyone that has cooked seeds and its in plenty of books to use a mat. Grow shops recommend them etc,
I just feel strongly they cause problems.