A question I get asked a lot is "what kind of yoga mat should I get?". I suppose its a real question these days post the industrialisation of yoga, where mats can often retail for over $100. When I started practicing yoga about 20 years ago, sticky mats were not branded, you just got what you could find, and you would put it in the washing machine to clean. Many people would still do this today and its a very viable and low cost option.
One thing I do notice teaching yoga in a space with a hard wood floor, is that sometimes (for example in a pose like Anjaneyasana where you in are in low crescent lunge with your back knee on the floor, see pic) is that very thin mats do not offer enough cushioning for the back knee. The old school way of getting around this is to the fold the mat in from the side to provide extra cushioning, or place something like a towel underneath the knee. If however you are in the market for a new mat, consider the thickness of the mat you are getting. For my money, I'd be looking for at least 5mm thickness (probably more if you have sensitive knees). Of course the thicker you go, the heavier it is to cart around so consider whether you are constantly on the go and need to transport the mat, in which case you might trade some of the thickness for a lighter weight.
In the stronger classes I teach where we may be holding standing poses whilst getting hot and sweaty, its important to feel stable in the feet and not like you're going to slip. I've often gone to studios with expensive new mats and I often feel like I'm slipping, which can be quite distracting and take you out of your practice. I'm wondering if it takes some time to wear these new mats in before they are grippy, but I would think you would want it to be functional from Day 1 when you've spent a lot of money. In heated studios where people sweat a lot, mat towels (made to the size of the mat) appear to be quite popular to help with grip and absorbing sweat. Personally I don't like the additional clutter of a towel on top of my mat for practice, but each to their own. If you have one of those unbranded, regular sticky mats and feel like your grip is challenged, perhaps try putting it through the washing machine to see if that makes a difference before purchasing a new one.
So what kind of mat do I practice on? I use regular unbranded mats that I purchased from iyogaprops which are useful when I am travelling or teaching because they are quite lightweight and I can roll two together so I always have a spare (for someone who has either forgotten their mat, or for extra cushioning in my own practice). For my home practice, I've had my Jade mat for over 6 years and its served me well. I'm not sure which of their current models it's aligned to, but I think its the Elite S. Its thick and grippy, and after 6 years, the only damage is a tiny crater at one end of the mat. I'm sure there are other great mats out there, this just happens to be the one I use and am quite happy with.
Hope this helps and love to hear any comments or recommendations you have.