If you have a bit of a long face, like me, then a bit of a fringe will help a lot. But try not to get anything too blunt cut or it will look 'wiggy'. I'm a big fan of layers, especially around the face, they soften the look a lot. If you aren't ready to go and try some on at a wig store, then you'll have to do a bit of trial and error shopping. eBay is good, you can get some really good deals there, but always remember that you get what you pay for. Start out with inexpensive ones (but not 'party' or fancy dress' wigs) until you find a style and colour that you like and then invest in a more expensive one in the same style/colour later.
Experiment a bit, it's not like you have to grow it out if you don't like it. The key is to have fun.
Mona xx
