You can get as involved in this whole game as you want to. At some point it's diminishing returns because it takes so much time and you're really not getting too much back for that time.

Remember to follow the golden rules:

1) Anytime you are doing something travel related sign up for the rewards program (hotel, airlines, car rentals) and register your purchases as you make them. These add up over time. For many years I never even registered for FFP's. I wasn't traveling that much but probably flew ten times internationally in a decade. That still would have been probably 80,000 miles if I had just bothered to copy/paste a number into a form.

2) As much as possible try to focus on just a few programs that fit your flying/stay schedule.

3) If you are the one doing the purchasing make a reasonable choice to get a lot of value off of credit cards. For example, the Amex Personal Rewards Gold gives 3 points per dollar on airfare purchases, and these transfer to a variety of partners directly as miles/points.

4) Take advantage of lucrative promotional offers like credit card sign up bonuses or bonus miles/points for hotel stays. You can do as much or as little of this as you want. But anyone with good credit can very easily make a 100,000-200,000 miles a year by just doing a signup on a single good card once every quarter. If you're a single person just wanting to get away once a year on vacation this is enough to give you business class to wherever you want once per year, provided you concentrate on a single program. If you're trying to accrue points for an entire family of course you have your work cut out for you.