1. Prime. I first heard of Urban Decay's Primer Potion from people raving about it on the internet, but decied seventeen quid for such a tiny tube was just too much.
2. Find a decent shadow that you get on with. It's good to try different black shades (some are darker than others although they claim to be black). And sometimes finding dark and unusual shades in old unused pallets can end up new favorites if you use them right. I have found that in terms of budget ones, the Natural Collection black is pretty good, but if you are willing to splurge a bit then SugarPill in Bulletproof just can't be beaten. Its $12, which in pounds is about £7.27. Also its cruelty free :)
3. Even with the best of eyeshadows, decent application makes a world of difference. Invest in some decent Brushes and you won't regret it. My favourite brush is actually a really cheap one, but the size, shape and texture of the bristles are perfect for me.
4. Wet the brush! Even a crappy chalky textured shadow can be brought to life with a little water, just paint it on. I have found that the best way is to clean the bristles with a baby wipe right before you begin, dab the brush into the colour and blow off any excess before you apply. Instantly a mess free intense colour that will last!
On the left we have dry application, which has blended lines and not alot of depth to it, as opposed to wet application on the right, with bold outlines and intense colour.
Hope this helps! And good luck painting ;)