1-Drywall is one of the Toughest trades to master.You need to have a steady hand and a well experienced eye.So here is a few tips for you.
2-Always use 12mm Gypsum Boards,it's much stiffer and hides all the framing imperfections.
3-Its Always wise to cover the entire floor of the room before you start Skimming the board and always Skimm the entire board or wall than only to patch the joints.
4-Thicker Panels means more sound resistance for that specific room,and also have fire resistant properties.
5-Always sand the entire wall to flatten out all imperfections.
6-Last but not least,you should always prepare before you start sanding the drywall.Cover the floor in the room first with drop sheets.Secondly turn off the air conditioning and close of any vents so that the dust isn't drawn into the system.And always wear protective eyewear and a mask.
We hope that these few tips will be of great advantage.