Don't over wash, for starters. It seems most people are obsessed with washing their hair at least every other day for the purposes of being "clean", but if your hair isn't greasy it doesn't need shampoo. Most environmental debris and even sweat will come out with just warm water or conditioner. Just my 2 cent on that. You may, of course, have a hair type that requires that frequency of washing and if that is the case then by all means.
Otherwise, you might consider looking into using an apple cider vinegar rinse. It helps with shine, frizziness...the works. The generic recipe for this is: 1 part apple cider vinegar and 2-4 parts water (2 for oily hair 4 for dry), adjusting along the way depending on how your hair reacts. Mix it up and pour it over your hair before you get out of the shower. Some people rinse some of it out, others don't. I prefer not to, but that's up to you. Yes, your hair will smell like vinegar while it is drying, but the smell will be gone by the time it's dry, especially if you use more than 2 parts water. Worst case scenario it's nothing a little spritz of body spray or perfume won't fix.
If you have frequent split ends and/or breakage of any sort you might consider doing the occasional protein treatment as I've noticed this can help with frizz as well. You can either buy these at somewhere like a beauty supply or you can make your own. The DIY egg mask (consult Google) is an example of this, but I prefer to purchase mine for a number of reasons.
You also have the option of using product lines with keratin in them. I've seen this option work well for a number of people, but I don't personally care for it. If you go this route, disregard the idea of protein treatments because the two together is too much protein. Also, if you decide to try these products a clarifying shampoo might be necessary once a month or so as sometimes these products can cause buildup on the hair.
Keatin treatments are also an option, but typically they are pricey, time consuming, and will generally remove most of your natural texture. Not a good option unless you prefer to have your hair straight all of the time.
Lastly, you might consider demi permanent hair color. It has a very low amount of peroxide in it so it isn't particularly damaging and it isn't fully permanent so it will fade out. Just if you go this route get someone to advise you as demi's generally run dark so usually you'll want to go about 2 shades lighter than your hair actually is. I mention this because the slight amount of chemical processing from this sort of dye tends to alter how people's hair behaves...in a good way.
This is all based on working at a beauty supply for 2 years where I spent 40 hours a week dealing with hair problems. Also, up until earlier this year I've always had long hair. Prior to chopping off a massive amount of it twice my hair was around 32 inches.