Break your team up into 2 or 3 teams. If you do 2 teams you’ll need 8 or 9 on a team with a player for each defensive position. If you only have 8 on a team you can eliminate either the pitcher, catcher, or one outfielder based on what is a priority for your team that day.  If  you only have 12-15 players on your team break it up into 3 teams of 4-5. Then place two of the teams on defense and one team hitting fungoes. No matter what, have the teams and batting orders pre-made before practice. This will eliminate unnecessary downtime during practice.
The main goal of the game is to hit it to the pin in the least amount of strokes, similar to golf. Holes can consist of a certain sign in the outfield, in the tarp tunnel, off of the foul pole, onto the pitchers mound or off of a yardage marker on the outfield wall; it can really be anything on the field that can be hit without breaking. There can even be 2 part holes such as: First you have to hit the ball off of the scoreboard, then you have to hit the ball off of the right field foul pole.
Players can also create complex holes such as ‘two-part holes’ where the players must hit or reach one object before attempting to shoot at the hole. For example, a ‘two-part hole’ could consist of hitting the scoreboard first, and then once they have hit the scoreboard they must hit the ball back to home plate, that would be one hole with the player with the fewest strokes winning the hole. ‘Two-part holes’ are typically saved for the last hole in order to make things more complex and difficult on the leader.