It turns out one hell of alot cheaper once you get used to it, follow the guide lines and use a good calculator such as "e juice me up". mix small quantities (5ml) for a start to see if its how you like it, then you can mix larger amounts. As stated above read the threads in the forum. Might be a good idea to buy a mixing kit for a start which will come with instructions, then you can buy the required stuff separately from then on. I get my PG/VG from Boots Chemist - not at the same time though, as they do not like or understand vaping so i tell them its for a disco smoke machine. VG is not a problem because Glycerine is freely available near the cough stuff. PG however needs to be ordered and they will ask you what its for (Disco etc'). I use syringes to measure the correct amount, again available from eBay or online ecig vendors etc.
Give it a go - you will not regret it. Some flavours you will love - some you will hate. Same as alot of things in life.