The best detergents for washing denim are both gentle and color safe. For indigo and other dark denim, we recommend using a detergent made for dark clothes specifically. Do not use bleach to wash denim – even if it's white – since you could end up yellowing the material. To help set colors on jeans that bleed or fade, wash the denim with a half cup of white vinegar to naturally cleanse and set the dye.
To keep your jeans fresh in between washes, you might try freezing them overnight every month or so. The theory is that freezing temperatures help to kill bacteria and odors that build up after prolonged wear. While freezing your jeans isn't a replacement for washing the jeans as needed (since built-up dirt and grime can also deteriorate your jeans), freezing could help extend the time between washes while combatting smells and germs.
Ironing your jeans isn't usually recommended, since extreme heat can shorten the lifespan of denim fabric. However, if you have creases you want to soften, using a steamer or placing a cloth between the iron and the denim fabric can help soften wrinkles more gently. If you have the time, you can also hang jeans in the bathroom while you take a hot shower, and smooth out the wrinkles afterward.