Point number 1 is extremely true. You can convince yourself there will always be a better time to launch. The one caveat I would add to part 1 is that you spend at least a little time making sure there is an audience before you spend lots of time building something. You need honest real opinions from people as to whether they would pay for your product or service if it existed. Ideally you are getting paying customers before you have even launched to validate your offering or service. Wasted time can eat you alive. Once you have validation though, Corbett is right. Just launch there is no better time than now. You can fix all the problems later.
If you’ve mostly been buying print ads, consider web-based ads. If you have tried Google Adwords, you might want to try to advertise on Bing or Facebook. Try sending out a newsletter by email, and don’t forget about social media. If you have a B2B target market, you could start your own business networking group. The key is to always try at least one new marketing technique. If it works, great, keep doing it. If it doesn’t work, try something else. Entrepreneurship is about experimenting with new ideas.
There’s more to being a coach or personal trainer than just being fit and loving to exercise. Finding a specialization is important, and licenses might be required for certain types of coaching roles. For instance, a friend in Boston obtained US and European soccer-coaching licenses before opening a successful one-on-one soccer-instruction business.