Wrapping in the correct direction (clockwise when looking at the pipe end) ensures the tape tightens onto the threads as the fitting is screwed on. If wrapped counter-clockwise, the tape can unwind and bunch up, preventing a proper seal and causing leaks. Always double-check your wrapping direction before assembling the joint to avoid this common mistake.

For most standard plumbing connections, 3 to 5 layers of Teflon tape are sufficient. The goal is to fill the thread gaps without overfilling, which could make it difficult to screw the fitting on or even damage the threads. For larger pipes or coarser threads, you might need a few more wraps, up to 7, but avoid excessive bulk.

Yes, pipe dope can be used as an alternative or in conjunction with Teflon tape for an extra layer of sealing, especially in high-pressure applications. When used together, apply the tape first, then a thin layer of pipe dope over the tape. Always check that the pipe dope is compatible with your specific pipe material and the fluids it will carry.

The most common mistakes include wrapping in the wrong direction, not applying enough tension, or using too much tape. Ensure the tape is wrapped clockwise (looking at the pipe end) with firm tension, allowing it to conform to the threads. Aim for 3-5 smooth, even layers that fully cover the threads, leaving the first thread exposed.