For a starter grooming kit, it is best to have a 4F, 5F, 7F, 10, 15 and 30 blades. These are the most common sizes that are needed in a beginner grooming kit and generally, are used on a daily basis. The 4,5,7 blades give the option of a variety of lengths from longest to short but not bald. The 10 blade is ideal for sanitary clipping and the 15 and 30 lengths are typically used in a surgical setting or underneath attachment combs.