I do 3 filters per week.
Clean the filter first. Get some filter cleaner. For a long time, I got those K&N filter kits from crappy tire.
Take the filter out and off the cage, get and loose dirt off of it, but make sure you're not just rubbing it deeper in to the filter.
Take the filter cleaning solution, and soak the filter with it, work it in a little bit, let it sit about 10 min, then rinse with water FROM THE INSIDE with a decent amount of pressure. Wring the filter out gently, then use a dry paper towel to soak up as much moisture as possible and let it dry.
Once dry, take the filter oil spray, and coat the filter with it, and scrunch the filter up once coated to get the oil in there good or to get rid of excess. It should be uniformly covered, and soaked but not so much that it's dripping when you squeeze it.
Don't forget your filter rim grease.
If you're lucky and have a really cool spousal unit, you can get no-toil powder cleaner, and throw in 120ml of the powder with 120ml of your normal laundry detergent in to the washer on low water setting and let it do the work for you. I do it that way with all 3 at once.
I use the ipone oil in a huge aerosol can from Royal for my oil now. Just better bang for the buck, one can has lasted me almost all season. Some guys hate the spray on oil, but I have never had an issue with dirt getting by my filters and I ride gopher dunes so you can't get much better air filter testing than that place.