Is 'making a strong commitment' a good idea? Is it a good idea to make a strong commitment\determination  to be mindful or to meditate? 

If we can't really control what we do in the future, is there a use to make a commitment? 

And if the answer is yes   - how to make it ?

I would love to hear tips on how to make the commitment/determination better.

And I would also like to hear your opinion about celibacy in this context - including celibacy from tasty food and from funny videos, from music, from entertainment in general, etc.
To make a  strong commitment,  you want to cultivate right effort by making a continuous effort, by hanging out with wise spiritual friends, by balancing energy with concentration and by not doing things that suck the energy out of you like reacting to your arising defilements, eating too much and getting lost in mental proliferation.

As Ajahn Chah says "Just do it".

Edit 

One could reflect on death. This can really be motivating because it lets us know we are pressed for time not just on the surface but in the heart as well.