General Tips

You should only place 3 to 4 pieces before looking for a solution. However, going from using 3 previews to 7 is difficult, so just try to increase how many previews you use by 1 or 2 till you eventually reach using all 7.

Try to make shapes that accommodate for many different pieces. The L, J, and T piece are good for this since they can fit nicely with every piece, but try to save some for the solution.

Take your entire queue into account when choosing what setup to make. Sometimes the "best" setup based on the first 3 pieces is bad because of the pieces after it. Best chance field doesn't take this into account which is one reason why it isn't recommended.

Don't make piece dependencies unless you absolutely have to. If you do have to, only make piece dependencies for pieces you see in queue or pieces that you know are coming up. Also, you should only make a maximum of 1 dependency . If you made a 4 piece setup that has 2 piece dependencies, you essentially made a 6 piece setup.

Don't use multiple T pieces to make boxes. In general, boxes are good, but avoid using T pieces to make boxes since T pieces are very good for solutions.

Know alternate ways to build shapes. For example, you can build PCO with S, Z, and T pieces, but there are other ways to build it using different pieces.

Try to find solutions that save good pieces. What's considered a "good piece" changes depending on multiple factors. But in general, avoid saving the S and Z piece and try to save the T piece when possible.

It's very hard to think about 6+ pieces at a time, so it's helpful split the solution into parts that you are already comfortable with. For example, if you placed JOL as a 3×4 box for your setup, like in the leftmost setup, and your queue is TIJZSZL, you're probably not going to be able to immediately see the solution. But by seeing that TIJZ can make the PCO shape, and that SZL can solve the PCO shape, you can still find the PC.