The version that works on the first try
Using Jitabi is closer to texting a capable friend than filling a form. You send what you know, it drafts a page, and you answer that draft with the changes you want. The one habit that pays off is making the first message a little more complete than feels natural: four facts carry the whole draft, and a careful paragraph there saves three rounds of edits later.
Those four facts are the occasion, the date, a rough time, and the place. Everything else โ the dress note, the line about gifts, the wording of the welcome โ can arrive after you have seen what it made. The draft is a starting point you react to, and reacting is far easier than composing from a blank page.