1 - A hot drink. This seems like an obvious one, but my rule is actually to have a hot drink a whole hour before I go to bed. Nobody wants to feel all relaxed and drifting off just to be woken by the call of nature do they? Plus this means that your going to bed mindset begins a whole hour before you intend to go, which I feel helps me relax a lot earlier. At the moment I'm favouring herbal teas, especially this Lemon, Ginger and Honey variety from Sainsbury's.
2 - A bit of pre-bed pampering. I always take my make up off as soon as I get into the house for the evening, but I now leave the rest of my routine until I go to bed, as I find it really does relax me to have a bit of a pamper and feel good about myself before bed. Simple things like moisturising my face or moisturising my whole body with something that smells really yummy just seem to work! At the moment I find the scent of Garnier Oil Beauty Moisturising Lotion really relaxing. If you have more time then run a deep bubble bath and have a good soak.
3 - A scented candle. But you have to get one that works for you. Try out a few candles outside of the bedroom first, as you don't want to have to try and sleep with an overpowering scent that you don't really like! If you have time for a bath then a scented candle is a great combo.
4 - Half an hour before bed with no technology. This is an important one and probably the one that I find makes the most difference. No technology means no TV, no computer, no phone, no tablet. Have half an hour before bed (I prefer to do this in bed) of something relaxing you enjoy like reading a book or magazine or just jotting things down.
5 - A decrease in light. During that half hour of no technology a great way to wind down is to dim your light if you have a dimmer switch or use a lamp instead of the main light. Obviously if you are reading then don't strain your eyes, but I find that even using a bright lamp to read with and having the main light off creates a bedtime mindset.
6 - Keep a notepad and pen next to your bed. This is one that I've only started doing recently. Those million things that you suddenly remember when you're in bed? Quickly jot them down so they're not on your mind anymore. I find it almost gives me a sense of closure when I write them down as I know I won't forget in the morning so I don't need to think about them so much while I'm trying to sleep.
I hope some of these points helped - please let me know in the comments if you have any other techniques for a better sleep!