Sometimes it is a case of you get what you pay for and a quid doesn't buy much these days.
I haven't tried any £1 juices although I've heard some are OK. If you're tempted, just buy ONE bottle that sounds like something you may like, don't buy loads. Most of my local vape shops sell 10ml bottles of 50/50 MTL juice for £4 each/3 for £10 or £5 each/3 for £12, generally I go for these and I have never had a bottle lacking in flavour, some I will never buy again because I didn't care for the flavour much but so far none have seemed too diluted.
It is bizarre that I like the taste of menthol and eucalyptus sweets but find vaping it disgusting (it also hurts my throat and make me cough my guts up). I don't care for mints as I find them boring really fast, but really like juices with mint added instead of menthol - so there is no guarantee that you will like vaping a flavour you like eating.
I would play safe and try buying a small selection if your local vape shops do multi buy offers, maybe one fruit, one desert/bakery and one soda. If you find ones you like try to buy them again next time and a new flavour to try out.
It can take a while to actually find out what your preferences are so all you can really do is try to buy flavours that you think will suit your tastes and add an extra 'maybe' juice now and again to try out.
I know its no consolation but Heisenburg is a notorious Love/Hate juice, I've only bought it once and still throw up in my mouth a little when I think about it.