i am starting into painting my interior. i am just going to use rustoleum and i want to make it look good. how should i go about this. i assume i should sand the orriginal paint or something like that. what grit? i will use primer probably 2 layers to be safe. then the paint, and probably follow up with a clear acrylic. is this about right. is it necessary to completely remove the paint down to metal first or can i just sand it then use primer. any help would be greatly appreciated. thanks.