Let me share with you a few things I've learned about finishing sheetrock. If you're experienced in this area, I won't be much help. But if you're a newbie like me, this might be useful.
#1- PAPER tape is a nightmare.
FIBERGLASS MESH ADHESIVE tape is the only way to go.
Now, there may be some reason that somebody prefers the other stuff, and maybe I just don't know enough about the process to know why it would be better, but I find the mesh stuff waaaaaay better to work with. I started out with the paper tape and didn't really feel like I was struggling with it, but one seam bubbled when it dried. And when I switched to the mesh tape, it was sooo easy to handle. With the paper tape, you spread on mud, bed the tape into it, then trowel off the excess mud as you smooth the tape down into the mud. With mesh tape, you lay the tape over the seam using the adhesive side, then trowel mud over it and smooth it down. No chance of bubbles.
#2- If you don't trust me and you go ahead and use paper tape and the paper tape bubbles, it is possible to repair the damage. I had a section of tape from the ceiling to the middle of the wall that had bubbles spread along it. I had three coats of mud on the tape (the coat it was embedded in, and two coats over it.) I just took a utility knife, cut out the entire section of tape, (which was very easy), laid in mesh tape over the joint, and mudded over it.
#3- I had several screw heads that stayed too far above the surface of the drywall. I had tried to set them deeper without success and then just mudded over them. When we sanded they were exposed again. I got a new dimple bit, scraped off the mud over the head, UNscrewed them a bit, then reset them. This worked with most of them. There is one that is stripped so we can't get it in or out. I just have to build the mud up over it and sand with care. If you can't get a screw to set and it ISN'T stripped, just remove it, mud the hole, and put in a new screw a couple inches beyond it on the joint.
#4- There seem to be 2 schools of thought about this process. Some folks will tell you it's all in the sanding. Other folks will tell you it's all in the mudding. I lean more toward the mudding. There really is a fine line between too much mud and not enough. As one book said, "There's no need to trowel on 5 gallons of mud and sand off 3." However, attention to detail in sanding is also crucial. And you must be patient. I only sanded after the final coat, but then found lots of places that needed to be touched up- screw heads, low spots, furred tape or drywall paper. I REALLY wanted to be done, but I touched up and sanded again. Do this as many times as necessary to achieve the smooth finish you're looking for. You'll be glad in the long run.
#5- Lastly, for now, is invest in a corner trowel.
The book I read did not even mention corner trowels. My corners looked terrible and I was dreading how much attention they were going to need to get them looking nice. Luckily, my mother came to visit and said, "Did you use a corner trowel?" "Corner trowel!?" said I. "What pray tell is a corner trowel? It sounds divine!" I sent my dear husband out for a corner trowel then slapped a coat of mud up in the corners with that. What a huge difference! They are now like buttah.
I still have to sand again and see where I'm at. If I think of any more tips and tidbits to share, I will. Wish me luck. The carpet is supposed to be installed on Friday. I'm running out of time!