How to get the freshest smelling laundry.?

I’ve been having trouble with my freshly clean laundry smelling a little dingy.

What can I do for fresh smelling laundry? I heard it’s good to use bleach on towels, but I have cute colored ones and don’t want them to get bleach spots all over them.

I’m not sure what I’m doing wrong! I have an older washing machine, which may be the issue, I don’t know. I do my towels serpate. I don’t over stuff them, or under dry them. I use the amount of detergent that’s on the back of the bottle. I use “large load” when it is indeed a large load. And I use cold water.

Any ideas, tips or suggestions? Maybe name brands that work the most or anything really! I want my towels to smell really good when I go to dry off or my clothes when I put them on. They either smell like nothing or like mildew.