This last night I got some insane dream journal material to work with, because for some reason I woke up twice during the night and I was able to record five dreams. 
I went to bed at 10 PM and woke up at midnight with excellent dream recall, then I woke up again at about 3 AM and then finally at 5 AM.
I was wondering if there are any methods that will make you wake up like this without necessarily having to use an alarm clock?
Also, what do you think could have caused this?
Most people have several mini-awakenings each night which mostly go unnoticed, they usually are awake for a few seconds, turn around and fall asleep again. To wake yourself up or to notice these short awakenings, you can use mantras like “I will wake up after every dream” (that’s the one I’ve used for a long time and it worked wonders). Your awakenings this night might have had several causes…Maybe your mind was still very active, or you concentrated a lot on DR.
Yeah, actually this last night I had decided once and for all to start a dream journal and stick to it, so it may have been because of my motivation and my excitement to record as many dreams as possible. 
With any luck this might work tonight again! 
Oh, by the way - how do these kinds of awakenings affect your sleep quality? 
I understand that everyone wakes up for a few seconds several times every night, but will you sleep more poorly if you actually notice all those awakenings and spend some time with your DJ?
Of course this can vary from person to person, but at least for me it never actually affected my sleep quality in a negative way. I guess it also won’t for you, if you don’t make a big fuss of writing your dreams down, like, turning the brightest light in your room on, getting completely out of bed, and thus probably disrupting your sleep cycles.
Another point IMO is that the positive things about waking up several times and writing into your DJ outweigh the negative ones, for example you’ll feel so euphoric about your DR success that you probably won’t even recognize if you’re tired or not. 
I don’t wanna brag or something but at the beginning of my journey toward lucidity I was so motivated that I was waking after what I believe every dream. I had so many things to record and that is gone now. I guess that this was true, genuine inspiration and that’s why I wrote before about motivation. I was so excited just because I knew that I will dream new and awesome, somewhat crazy things but it didn’t matter, it was what I wanted…
I guess your motivation is very high now, try not to lose that feeling and intention…
Oh and everything that Leijona said…
Good luck!
Thanks a lot for your answers.
However, for some reason my dream recall was at rock bottom this last night - I mean I did remember some fragments of a dream scene a few minutes after waking up, but it was on a really vague level like “ah I did that action at… some place… with someone… for some reason… and… … ” and my whole dream memory was probably just a few seconds.
What the heck…?
That happened to me last night, but it was only because I slept in on a school day, therefore I had no time to remember. All I remember is some Tic Tacs and an abandoned wooden shack in a thunderstorm. >.>
Funny thing is, my breath tasted terrible after I woke up, so the first thing I did was get a Tic Tac. 
Yes, like Antylamon said he had a change in a daily routine, you may not or may had the same situation but I wouldn’t worry to much. You can try and stick to daily routine which gave you a perfect DR but to be honest that is almost not possible. Even if you do the same things who knows how your emotions, feelings and other psychological factors will reflect on your DR.
Once when you do get real, learned DR not just some rebound then you will see the difference. Sometimes I don’t care if I remember just one dream if it was really vivid and detailed…
Yeah, well I did have some pretty nice DR this last night again (and woke up naturally several times during the night as well 
), but this time I didnt care about writing it down. 
Oh well, I will just need to write down everything tonight instead. ´
It seems like I tend to wake up like this much easier if I drink some coffee before going to bed.
By the way, it’s fascinating how easy it is to forget dreams.
I remember I had a dream that I was absolutely sure I would be able to remember until morning, but I barely remember where it took place - I know it was in the cafeteria at my workplace, but I don’t remember those “crystal clear memories” of what actually happened there.
Really kinda shows how elusive dreams can actually be.
I know I hate that. But that’s just a good example how we are not accustomed to remembering dreams… If they were important to us as daily things then we wouldn’t forget them so easily.
But we are on the good track, we at least remember dreams upon awakening, most of them don’t…