I usually think that you have to spend £££ to get good products. I've always used Nails Inc and Leighton Denny on my nails and, while they are good, they always chipped after a day despite using base and top coats. I've just bought a pot of Rimmel salon pro nail polish, it has a great wide brush and is so easy to apply. I haven't used a base or a top coat as I thought it was going to be rubbish, but 3 days later there isn't a chip in sight!
Any other things I could be saving my money on?