Word of Mouth works very well, espcially for sporting goods. Only way you can trust if they are of good quality is if you have a few people using it assuring you it is good.
Price is very important. And it depends who you are targeting. Generally, the equipment -say a bat- shouldn't be more expensive than its competitors. If you are aiming for school-level cricketers and kids, then it has to be very affordable so that parents won't be hesistant to buy it or so that kids can realistically save up for it. If you are going for pro-level, then you can afford to raise the price up a bit but still a little less than the competitors to attract people.
Advertising through media is always good. The ad has to be professional. As Bazzqueen said, you find a deo called Africa with fitting colours, it seems professional. The wrong clours, it seems ameaturish. Similary, for sporting goods, get across the image of either being a fast-paced, action packed kinda brand (Like RBK or Kookaburra bats), or something more classic and subtle (GN is the only one that comes to mind), and stick to it.
Promotional events, competitions, etc. all help.
But nothing beats word of mouth. Create your product, advertise like mad initially, keep the quality high, and then once people start buying it, hope for word to spread.
EDIT: Endorsements, as Kev said, does work. But how will a new bat company get endorsements initially? Seems a bit tricky to me. And I'm likely to never buy a Woodworm bat cause I feel KP is a bit of a prick, but since Bravo uses it I'm more likely to get one. So it does help if you can get someone famous to promote it.
as long as it's not you 
