QUOTE(over_loadcode @ May 31 2018, 04:02 PM)

I'm fairly new to Tetris (sprint time under 1 min) and I've had trouble stacking in confined areas of the grid (e.g. 4wide, some beginning setups)
I've seen people mention looking at all of the upcoming pieces, and I'm unsure on how to use that information. Do I plan out where to put each piece?
This is a good question. In multiplayer, there's no time to really stop and think of a formal plan for putting each of the 5 upcoming pieces. Instead, I'll look for key pieces. The best example is probably if I'm about to create an overhang for a T-Spin. If there are no T-pieces coming up, then it's probably better to wait, especially so if the overhang creates an unstable surface.
The same idea applies whenever I'm considering building a surface that creates any "piece dependency" such as an I-piece or J-piece. Normally it's bad, but if the needed piece is about to come, then it's ok.
At a fast pace, the process is subtle. I know by keeping an eye on the next pieces, I will sort of "absorb" that info and apply it automatically to stacking decisions without really thinking too carefully about it.