liquidcitrus | Tetris: Going From Absolutely Terrible To Sort Of Acceptable (Reply)

This does not have pictures in it, because I learn best from text descriptions. Also I don't have anything handy to make good Tetris pictures with. If someone else wants to do that, be my guest.

So I see a lot of people interested in Tetris 99 that want to know how to play Tetris. Yes, there's a whole lot of tutorials, but if you're still in the stage of "I'm just putting the pieces where they can fit and they're leaving holes", the tutorials probably won't be helpful to you.

What you want to learn first, and practice, is keeping the top edge of your stack almost horizontal.

Do not try to make the shape with a long canyon to try for Tetrises. You need a good foundation, both literally and metaphorically, before you will be able to pull that off consistently. Just clear single lines for now.
Leave at least one two-piece-wide flat spot for the yellow O piece to land on.
Leave at least one little bump for red Z pieces or green S pieces to land on.
If you have a canyon that is two blocks deep, try to put the orange L piece or the blue J piece into it before it gets any worse.
If the canyon is three blocks deep or more, put a cyan I piece into it.
Use the purple T piece to solve any other alignment issues. Seriously, that thing is super useful.
If you do end up with a buried hole under the surface layer, try to stack as few blocks as possible above it, so you can dig for it more easily. (This also applies if you get gray garbage blocks put underneath you.)

So: Almost horizontal.

After you master this - once you can keep your top edge flat for a while - then you can start trying to learn the other forms. But don't rush it.