Practice writing backwards through a mirror - you know, so you can read what you're writing in the mirror but not if you look directly on the page.
Buy a plastic model (circa 3rd grade blob of plastic and glue) and be as meticulous as you can be painting and connecting the parts. Make it pretty.
Carve soap. Use an exacto blade (found at any hobby shop), a sewing needle, or anything else with a fine blade/point. Carve whatever you want (doesn't have to be a tooth) paying attention to detail and scale.
Pre-clinic isn't so much about teeth. Rather, it gets you used to looking at/thinking about teeth. Carving a molar doesn't prepare you to prep a real crown - but it does train you to look at the prep and envision your final restoration. You can practice this "vision" with some of the exercises above. You can also do a search online for "dental anatomy" and draw what you see - make tooth #19 look different from tooth #31 from the occlusal view, buccal view, etc...