Gillybean, you said it heavy and full of debris not really seed compost.
My personal use is John Innes Number two, that is a recipe made up by several compost makers. A small bag of washed sand and small bag of small agricultural grit from any Garden Centre.
I have a mixing tray but a bucket or old dish will do, mix one scoop of JI compost one scoop washed sand and one scoop of grit and mix it well. This will be damp but not wet, if you dip a finger in it will come out with strands of soil on and not muddy.
Fill your trays or pots loosely, just give the tray or pot a tap on the bench, do not compress the compost. Scatter the seed and cover lightly with sieved compost or light grit, water with a Rose on the watering can, I water from the bottom in a tray of water for a few minutes, not soaking just damp on the top of the tray.
All seeds do need different conditions for germination, some very warm, some medium warm and some no need for artificial heat, read the packet for a guide.
Never over water, as soon as the seedlings have true leaves then pot on.
Two scoops of compost one scoop of grit one scoop of washed sand is the mix I use for that, your final pot on is just compost or into the ground.
Hope this helps Frank.