Space items out so water can reach every surface, then add one Super Clean™ washing tablet.
At least 4 bottles, up to 8 depending on your bottles' shape. Or a full set of pump parts.
Bottles angle in from the sides on the bottle attachments, which hold them at an angle so water does not pool on top and they wash and dry faster. Bottles also fit in the corners. The default 4-bottle arrangement is bottles on the sides, teats in the corners, collars and caps on top.
Pump parts angle in from the corners or the sides, with each of the 4 main large components over the 4 static jets, and all smaller accessories on the upper rack.
Only use Super Clean tablets. Other detergents foam and can damage the machine, which voids the warranty.