I have owned and operated (for 6.5 years) a successful math tutoring franchise called Mathnasium. My center has ranked in the top 10 (in terms of revenue) for each of the past four years (out of 900 centers).
To increase sales and help with a long term strategy would require significant time, money and dedication. There are several obvious things a business owner should do but may not do.
1: Customer is always #1. Treat all customers like gold and they will tell others about you. People not only buy products they like but mainly from people they like.
2: Treat employees really well. The way the owner acts is the way the employees act. Being nice is contagious. On the flip side being rude is contagious. Treat employees well and they will treat your customers well.
3: Marketing is something I see so many businesses skimp on. They say "I cannot spend $3,000 a month in marketing since my rent is $5,000 a month." Not marketing is like opening a business and not telling anyone you are there. Continue marketing even when you are busy and when marketing seems futile. If you ease off the gas your sales will drop. If your sales drop too much it may be difficult to save the business.
There are about a 100 other things you should do but if you do those three you will be very profitable.
For a long term strategy you need to track your metrics (sales, payroll, etc.) and follow the monthly changes in these metrics. If your payroll as a % of revenue is too high then maybe you are overstaffed or paying employees too much. If your customer complaints are too high then maybe you need to invest in training or process improvements. I use microsoft excel to track my metrics.
You also need to understand how to track your data and what data is useful. You can ask other franchisees, find info online, etc.
Best of luck!