I'll show you how my half steps + granny works here

If you want to pick a new chainring, plug your cogs and chainrings into the gear analyzer, and try different chainrings. Pick a chainring size that will minimize overlaps and give you the most gear options - narrow steps between gears. Especially look at the semi-log graph for gear spacing and overlaps. If it looks evenly spaced on the semi-log plot, it's perfect.

(printed and scanned this, but the download didn't pick up all the details)