Drywall taping may be the least exciting aspect of drywalling. But it's also the most crucial aspect when it comes to creating invisible--but strong--seams.
Problem: "My Inside Corners Look Ragged"
Fix: Try metal-faced inside corner paper tape. It's like paper tape on steroids--it creases in an instant and is a lot stronger than the paper-only tape.
Problem: "My Outside Corners Have Already Started to Chip Away"
Fix: You can use paper tape on outside corners.
But why not spend a few extra pennies and buy metal or plastic outside corner bead? Save the paper tape for outside corners that never receive any traffic, such as bulkheads or skylight areas.
Problem: "The Mud Has Already Started to Dry By the Time I Get the Paper Tape on the Inside Corners"
Fix: Before you lay the mud, pre-crease and cut to length your paper tape. You'll save yourself a crucial few seconds by doing this. Even if you use the metal-faced paper tape, you can save time by getting the tape ready ahead of time.
Problem: "My Drywall Tape Shows Through the Drywall Mud and Looks Terrible"
Fix: Remember, it's three coats of mud: tape coat, filler coat, and final coat. It might be that you are excluding that final coat. The tape will show through the filler coat. In fact, if it's not showing through, that's a cause for concern, because it means your filler coat is too thick.
Problem: "I Can't Hide My Mesh Tape on Butt Joints"
Fix: You cannot fix this.
Use paper tape, not mesh tape, on butt joints.
Problem: "I Can't Hide My Paper Tape on Butt-Faced Seams"
Fix: Butt joints are difficult. Since you have no papers creating a "valley" in which to hide the tape, the tape is riding on top of the drywall. Yes, it takes a patient hand, but you do need to carefully apply that final coat and feather it out well with your 10" or 12" knife.
Or the problem might just be that you're still using the 4" or 6" filler knife for that final, feather coat. In this case, go out and buy a 10-12" knife. It will make your life much easier.
Problem: "A Year Later, My Drywall Seams Have Already Started to Crack"
Fix: Mesh tape isn't a cure-all by itself. But combined with good taping technique, it can alleviate many of your cracking problems.
Also, it may seem counter-intuitive, but too much mudding compound applied in one coat will later cause cracks.