The hardest time for me to remember my dreams is after wakeing up of several hours asleep when i wake up on my own. I think this is mainly because theres more time between your REM cycle (dreaming state) and NREM (non dreaming) until you wake up. In short if your in NREM for awhile then wake up, alot of time has already passed since your dream ended but if you abrubtly wake someone up in the middle of a REM cycle they will useally remember there dream vividly since they were just in it two seconds again.

What i found works best not just for dream recall but greatly increses the chance of having a Lucid Dream is wake up a little bit earlier then you do and make sure you have plently of time before you have to go to work or whatever. Walk around your place get a drink of water then go back to bad and try to fall back asleep. If you do fall back asleep it will only be for about an hour and i alsmot always remember my dreams in this state and makes having Luicd dreams much more likely. This is also similar advice as to what to do to increase your chances to have a OBE.