For me, part of it depends on your own strengths and weaknesses. I'm a total spender. I know it. I'm not going to change it. It's just who I am. Thus, I learned to channel that more appropriately. I like properties to be paid off. (I know, some folks disagree, but that's another topic for another thread.) When I first bought my house, my mortgage was something like $700/month, but I always had just enough to get by, never more and never less. So, I decided my mortgage was $1000. In fact, I purposely didn't know the exact amount so I wouldn't be tempted to pay that amount in a "lean" month. Miraculously, I always found the $1000. Now, some months, perhaps due to a bonus or Christmas gifts or whatever, I'd have even more money. I'd put that toward the house as well. I knew I'd just waste it on something stupid if I didn't, so l managed paid it off in 12 1/2 years while making less than $30k. Not too bad for a spender. :-)
I joined the Army and after I paid off my house, I decided to add to my Thrift Savings Plan (Army 401K). I'd started at the recommended 10% when I joined, then every time I got a raise or a promotion, I bumped it up that same percentage until I reached 25%. For 7 years I never saw a raise in my actual pay check because it was all going to my TSP. I figured I managed to live on that amount last year, I can again this year.
Well, now that I got medically retired, I'm no longer able to contribute to that, so I'm back to figuring out what to do with my "extra" money so as not to waste it. I just bought a house. I bought it through a line of credit against my stock market because they wanted to close with cash and quickly. However, I plan to refinance to a traditional mortgage. Partly, I want to be able to free up that line of credit in case I need it again. Partly, because I'm just going to waste my money on something stupid if I don't get rid of it another way. Paying a mortgage seems like the perfect way. The renters will be paying it as well, so the house should get paid off very quickly. :-D
I'm not a saver, but I've found ways to have something set aside for the future. I always say, "Life isn't about being perfect. It's about working around your imperfections." If you know you can save, maybe split the difference between your 401K and your impending property purchase account. But if you know you can't save (no shame in it, just shame in not knowing it), then put it away in the 401K.
Take a good, realistic look at your abilities and your plans. See what fits best. :-) Good luck!