Most of them are captured in the following picture.
Unfortunately I cannot depict them all, so here are a few more:
- Do not use the component type name in its name, for example do not use Expenses Process, Submit Expenses Activity, Expenses Rejected Exception.
- Name a process so that its name fits in the following phrase: "the [Process Name] process", for example: "the Order Handling process".
- Give an activity a short, but meaningful name. So:
- Don't use uncommon abbreviations,
- To keep the reader focused on the keywords, do not capitalize prepositions and possessive pronouns ("Review and Finalize Order"),
- Avoid articles and pronouns ("Add Order Lines" instead of "Add all Lines to the Order").
- Name Catch Events, Business Exceptions, and Signal Events so that is reads like an answer to the question: "What happened?", "Well the Customer Cancelled".
Like most naming conventions, the prime reason is to have consistency. So don't treat it like a religion, and don't think that mine are better than yours. Of course they are, but just don't think that. Most of them are more like a guideline.
To help you with your choice, consider this:
- Using active verb-noun phrases is a psychological thing. Don't ask me why but somehow it helps your brains to determine the right scope of an activity. For example, one person may interpret Order Handling as one single activity (done by one person as one logical "transaction") while some other guy considers it to be a complete process. If you call it Handle Order that just "sounds" more like one single activity. It is not for nothing that this also is a de facto standard for use cases.
- Using the question mark for exclusive gateways helps with limiting the amount of text you have to put in the diagram, as all conditions on the outgoing sequence flows read as a simple answer to the question of the gateway.