In addition to the tips of the other commenters:
- The #1 way to remember more dreams is to be interested in them! The only personality trait correlated with high dream recall is "openness to experience" (https://en.wikipedia.org/wiki/Openness_to_experience#Dream_r...). If you want to remember dreams, first consider WHY you want to remember them. Hone into that curiosity and strengthen it.
- Second best tip I can think of is: more sleep! REM periods get longer in the later cycles of your sleep, meaning a higher chance of dreams.
- Also, if you really really want to recall dreams (and perhaps induce lucid ones) and you don't mind being tired the day after, try interrupting your sleep at ~90 min intervals (the average length of a sleep cycle) with a (silent) alarm clock - or raise a baby :)
- Finally, quit smoking weed if applicable, as it suppresses REM sleep ;-)