Since very dry skin tends to also be very sensitive, as is the case with me, you might find complete relief (and amazing skin) by using the philosophy line, especially 'hope in a jar' for dry/sensitive skin. that, plus the 'purity' cleanser, turned my skin around 100%. they have a website, philosophy.com so go have a look. they are in some US department stores, but i do not know about the UK.
Elizabeth Arden 8Hour cream. It is a complete miracle worker. It does sometimes cost a little more than most creams, but you only need a tiny amount so it lasts for ever!
Have you tried body-brushing? Start from the soles of the feet and work upwards towards the heart, with a brush from the chemist designed for this purpose. If you do it first thing in the morning it wakes you up beautifully! Exfoliate regularly, and apply any mositurizing body lotion after your shower.
The Body Shop body butter moisturisers are gorgeous to use but are pricey. I use one from Cyclax which is much cheaper, or some from Avon when on special offer. I have to use a moisturiser daily because of dry skin on my arms and legs and when they're really dry baby oil helps a lot. Apply baby oil after a bath or shower, onto wet skin, dry off then apply some body lotion. Take care with oily stuff in your bath in case you slip. Hope this helps.
Try teetree exfoliator or scrub, then use a gentle moisturiser, aqueous cream is a good one; this also stops any moisture escaping from the skin afterwards. If a tee tree scrub is not right then also try eucerin products there are a few different exfoliators and facial creams all made specifically for dry skin. Anything that foams will probably dry your skin out further.
Obviously the first thing is to drink lots of water, but for a no-nonsense and economic cream try Astral moisturiser. It's really good and isn't incredibly greasy like lots of other creams for dry skin, the good thing is that you can use on all of your body as well as your face.
When I get really dry patches I use evening primrose oil- a small drop massaged in before bed works really well. You can get it from superdrug for a few pounds
Invest in dermalogic intensive moisture balance - it's well worth the money and is great for dry skin. failing that a mashed avocado applied to the dry area works wonders, as does olive oil, left for 15 mins and removed with a cold flannel.
olive oil and sea salt also makes a great home made scrub for elbows and feet