I've been streak running (so running at least a mile per day with no exceptions, mostly 5ks during the week, 10-20k on weekends) for almost 8 years (2817 days). The single best tip I give to everyone is "slow down! run slow!"

Of course, almost no-one adheres to it unless they are already well practiced. It's just deeply ingrained in peoples heads that "only if it's hard or painful it must work". Then people check out of running because it feels like crap, which it does if you always push too hard.

In my opinion, three of the most important rules are:

- slow down! does it feel "too slow"? Great, that's the right speed for most runs

- small steps! feels awkward at first, but is sooo much more efficient and soo much better for your joints

- land on mid- or forefoot (that happens mostly automatically with small steps)