Puzzle discussions here.
Here are some hints that can help with puzzles:
1. Look at the last shape and think how your board should look like at the last step. For example if the last shape is the 2x2 box, then you'll probably need to build 2x8 row of blocks for it.
2. Count blocks on the board. If the number is not multiple of 4 (4,8,12,16...) - this means that at some point you will need to clear several horizontal AND vertical lines at the same time.
3. Some puzzles invite you to make the wrong move. If you see a nice gap in blocks and it looks very suitable for current shape - this is probably a trap.