Get an ice cube tray and put slices of orange, lemon and lime in them. Then fill mup with water and put in freezer. Then put your ice cubes in the water and not only will they make your water lovely and ice-cold but you will also get a hint of taste from the fruit. Also, try doing more exercise etc. which means you will need to drink 8 glasses of water rather than forcing yourself to drink them.
Try drinking them out of crystal glasses. It makes the water seem special. I bought a few different fancy glasses from a store where you can buy one or two and not a whole set, so that have a choice of goblets, stemware and other cocktail styles. They make water and herbal ice tea feel like a luxury.
Just putting ice in them in general really helps as it makes the water more appetizing whereas luke warm water kind of puts you off the idea of drinking it at all!
I find that if your used to drinking Teas and Coffee, if you drink your water heated it seems to go down easier and you can drink at least two glasses at a time without much problem