Preparation
Gathering the tools you need is the first step. One invaluable item is a detachable shower nozzle or a faucet attachment that sprays water. Next, choose a liquid, not a gritty, cleaner to clean your tub. Make a homemade cleaner by filling a spray bottle with equal parts of vinegar and warm water, plus a few teaspoons of ammonia. You also will need a microfiber towel and a mop.
Light Cleaning
Spray the entire tub down with the solution of your choice. Allow it to sit for a few minutes to penetrate soap scum and dirt. If the tub is not very dirty, you should be able to simply rinse it out with a shower attachment.
Heavy Duty Cleaning
If your garden tub has a ring of soap scum, or the kids have been playing in it with bath-time finger paints, you will need to scrub the tub. Use a mop to clean the tub thoroughly from top to bottom; the mop lets you reach difficult-to-access areas. Rinse well with the shower attachment.
Drying and Polishing
Many bathtubs and garden tubs dry with water spots that can make them look still dirty after they have been cleaned. Wrap a microfiber towel around the mop's head and use it to dry and buff your garden tub.