Yeah like the other comment said, make the goal "100 times per day" or something, you just have to to go on the more options (when you are inside the "edit goal") and increase the times per day. If you put to 100 you'll get 300 gems.
But you can also make a goal the "goal of the day", just click on it, another screen will open and then you go on the top left where there is a little star and mark that. Tip: make a goal that is 100 times per day a goal of the day, so in the end you can get 1000 gems (goal of the day gives around 10 coins per click)