The fastest answers come from tickets that carry everything we need on the first pass.
Say what, where and when
Name the service or invoice, say what you expected and what happened instead, and when it started. "Invoice #1042 shows tax twice" is answered in one reply; "billing is wrong" needs three.
Include the evidence
Attach a screenshot or paste the exact error message. If it is about an email, forward the email into the ticket rather than describing it.
One subject per ticket
Two problems in one ticket are handled by two people and neither can close it. Open a second ticket; it is no extra work for you and much less for us.
Check the suggestions
As you type the subject, matching knowledgebase articles appear beside the form. Some questions are answered before the ticket is sent.