Set goals little goals, big goals, football goals, smart goals.
There's nothing like goals to bring people together and build motivation.
If you have a consistent group you can try setting public goals. These are personal goals set by each individual but you put them somewhere everyone can see them. This has a few benefits- people can offer help, they can gain inspiration, they can offer encouragement. More importantly when a person reaches their goal everyone knows that it mattered to them.
You can also make group goals- something everyone wants to achieve.
This is also an opportunity to talk about setting realistic goals.