The Physical Details of Sitting
Sit in a place that's quiet and comfortable. Where the bugs won't bug you. Not too hot and not too cold.
You'll want a special sitting place. A corner or a room reserved just for sitting.
Refrain from eating at least 3 hours beforehand.
Wear something loose. Or nothing.
Sit in a posture that's comfortable and stable (see the pictures below).
When you're sitting, breath slowly from your belly. When you inhale your belly expands and when you exhale it contracts.
I like sitting first thing in the morning.
Experiment with your sitting schedule.
Sometimes, when you have a few free days, try dedicating all your time to sitting. Sit, go for a walk, sit again, pull some weeds, sit, etc.
This is how you sit on a seiza bench.
(And here's how you make one)