I will eventually choose to be bald but right now I am only 19 years old! My hairline is receding and I'm balding, I want to keep my hair for maybe 4 years, JEEZ! Any tips? thanks. 
Because I'm one of the very newest members here, I will give you some shave-free alternatives.
1) Take Propecia, a prescription drug, to preserve the hair you have. I believe the generic name is finasteride. No jar for your your shorn locks needed. See your physician for more about this.
2) Use Rogaine, alias minoxidil, to regrow hair on the top of your head. I used minoxidil a long time then took the easy pill route above. Do not do this. Propecia does not usually regrow hair on the top of your head. Based on both my experience -- eons in balding years -- and what I've read, minoxidil has to be part of your treatment. A good result with it appears to be a miracle.
You may achieve good enough results with Rogaine(r) alone to skip the finasteride pills altogether. The problem with Rogaine is you must apply it 2X a day and because you're putting it on a bald spot, it runs off your head like water. They have a more convenient foam but there is no generic and you'll pay almost $50 a month for that increased application convenience.
Any OTC baldness remedies, no matter how cleverly hyped, that really work contain minoxidil.
The minoxidil route is slightly more time consuming than maintaining your chrome dome through shaving. (Shave 1x per day; apply minoxidil 2x a day.) However, given your age, I do understand why you would choose that approach.