Years ago we picked up a little g plan wardrobe which wasn't very practical so I added shelves. I made an internal frame out of cheap pine batons and used mdf shelves which are held up by these brass shelf pins.
I didn't do anything fancy just drilled holes to fit the pins.
You can buy cabinet shelf hole jigs so they are evenly spaced. Or you could create your own jig by drilling holes in a piece of scrap so that even if your holes arent perfectly spaced, at least they are consistently not evenly spaced on both sides
Cheers both.
@fredtc I think that's over complicating it, I'll just use screw/push in pins.