Just because something is stained does not mean that it needs to be trashed!  I have learned through lots of trial and error, some of the best things for removing stains.  If a clothing item is white, you are in luck.  Mary Ellen makes a product called Formula 1 for set in stains.  This truly is a miracle.  Just squirt a little on the stain and it disappears in a minute or two right before your eyes.  Rinse clothing and wash like normal.  Be VERY careful not to get it on your own clothing because the second it touches any color it eats it up.  I have also had luck with her Mildew removing products, some of her products I am not so impressed with.  Her products are somewhat hard to find in stores, around here Byerly's and Lund's stock them, you can also purchase online at maryellenproducts.com.  I am not affiliated with them in any way.

For colored clothing, my favorite stain remover that almost always works is dual action shout.  Pour that on, let it sit for a few minutes, scrub vigorously with a toothbrush (I swear, I have done this with lots of things, it works!). Then wash.

Tide is by far the best detergent for removing stains.  I have tried everything on the market, and I always come back to it. 

Check to make sure the stain is gone before you put something in the dryer (if it's not, re-treat it), because once in there, the stain is pretty much baked in.

Don't waste your time and money on other stuff.  I have purchased so many stain removal products that don't do any good, but wanted to share these stars that really do work.