You can do day trips to Stirling and Edinburgh with no problems.  One of the most affordable ways to travel within Scotland is the Citi link bus system.  It takes about the same time as the train with stops and is more than half the price.  The coaches are nice and reasonably comfrotable. The buses leave regularly to the main cities i.e. Edinburgh but not as often to less visited cities or towns. Comparison prices (just for example): Edinburgh from Glasgow- 12 pounds (2 people) and a one way train ticket from Glasgow to Edinburgh might be 18 pounds (2 people).  The bus stations are in the city centers or nearby so you have easy access by foot or public transportation. have fun.