Over the years I have always gone for the bras described with words such as; maximise, enhance, boost, heavenly lift etc basically just push your boobs up to the absolute limit. But since becoming more comfortable with my body, I have started buying properly fitted bras, shopping in underwear specific shops and finding bras that will complement my boobs.
I vary between a B and a C cup depending on the shop (I would always recommend trying bras on before purchasing, there's nothing worse than buying the most beautiful looking bra, getting it home and it not fitting quite right or being really uncomfortable!) and I have tried different shapes and have finally found my favourite style.
Small boobs, in my opinion, look best in triangle bras! Although they don't offer a huge amount of support or give you much emphasis on your cleavage, they look so elegant and pretty.
I recently went into h&m and found a beautiful black lace triangle bra in a two back with a cheetah print one (which isn't so great on me because of the pale colours) for £7.99. I would easily spend £8 on a single bra so getting two for that price was something I couldn't say no to. The only downside is that they didn't come with matching underwear but they are so flattering and really boost my confidence.
Something else I would recommend is getting properly measured because you may be surprised at the size you are buying being completely different to your actual size.