For many years I used Creative's Formation Tips. I'm now using EzFlow, so I'm using their Leisure Tips and Glass Leisure Tips. I also have their Classic French Tips, but I've only used them a few times.
If you ring and ask, they may send samples. We certainly used to, although it was a 'mixed bag', so you didn't necessarily get all the sizes but certainly enough to get the feel of the tip.
Velocity is a great tip and the number one seller although No 1 used to be Formation, but that has been beaten into second place.
Velocity is a micro well tip that blends very fast indeed. Most of the 'pre-tailoring work has been done for you and it suits 99% of nail types and as it is slightly tapered it gives a very sleek look to either a square form or oval (cuts way down on filing and shaping). It comes in natural, clear or French White.