It takes time to learn the proper techniques of applying joint compound and taping the corners and seams of your drywall. This video offers some simple tips to get you started in the right direction. Make sure to mix the joint compound well, even if you are using the premixed type. This helps get the air bubbles out of mud.Also only don't mix too much joint compound. Mix only what you think you can use before it starts to dry. Pay a little extra and get the right tools for the job, you'll notice the difference in the finished product.