The easiest way then is to build a time machine :p then hodl as people say but I dont think there is any simple way only happy accidents.   If I had saved my first experiments with bitcoin mining that only amounted to 0.1 or so on each occasion I would be much happier now but back then 0.1 wasnt anything so I didnt respect the whole process of storing the wallet even accidentally keeping it somewhere.   Theres always a risk of some kind involved.

  More realistically, the way to get bitcoin is correctly predict price direction.   Too many thought $10,000 would be the recent ceiling but in fact it did go far past that before receding, anyone who could understand both movement and be long and short would be earning quite well.    If I had to call a direction right now I think its stuck in a sideways consolidation type pattern (I'm being positive in this view imo), so we'll see in a few days I guess.  Not sure this is as profitable as calling a top price for the week.

Arbitrage or intermediary services is another idea, bridge two prices which are incorrect.  Buy the lower, sell higher.   Thats hoping others dont copy your actions and fill the gap.   The other way to earn BTC is be very talented at something in a unique way, some people design for BTC.
  Some of the richest people have enabled easy payment services for online, bitcoin is part of that of course; if you can do this you are part of every retail % margin without the involved risk of investment specifically.  This is the cleverest design to make BTC