Service Tasks with different templates form palette

Hello, I have a simple BPMN Modeler, with custom templates for Service Tasks. I would like to do some custom pallette icon what will be a shortcut with a predefined template, so user dont need to drag a service task and then selects e.g. Function Node template (my custom template) but he will have a icon in sidebar what will be bpmn:ServiceTask with my Function Node template. I am not really able to find some good example for this, any suggestions please? Thank you.

Could you link additional resources for the concepts you describe? I.e. what do you refer to as custom templates, select ... and so on. Also helpful: What is your context? Modeling for execution? If so, what run-time do you target?

That helps us to understand your concrete context better, and help more effectively.