First, buy either a 4" or 6" taping knife,& a mud pan. Apply a liberal amount of mud on seam of wall, but keep it smooth and about as wide as the blade you choose to use. Then, take your tape and apply it to the seam you just mudded, then take your blade and push the tape down into the mud. Re-mud over the tape. Let dry 24hrs. You'll have to mud the wall 2 to 3 times in all before you're finished. Letting each coat dry 24 hours.