It's a pretty simple checklist to ask a good, narrowly-scoped recommendation question. I'll make a rough outline here, I'm currently revising this (which is based on the original ground rules that I posted pre-launch).
1. Straight to the point, succinct title
Don't use words like 'best' or 'good' - just tell us what you want. We're not going to recommend the worst, or bad software. What [editor/utility/program/plugin] does [task] in [manner]?
2. Describe your task
Tell us what you're doing, or intend to do with what we recommend. If you're bulk re-sizing a bunch of pictures while converting them to another format, or backing up lots of files and trying to avoid data duplication - let us know with as many specifics as you think might be relevant.
3. Describe what you have, if anything, and what you don't like about it
This can sometimes be optional, but let us know what you've got or what you've tried and didn't like, and why. Let us know if you looked at something and decided it wasn't for you. Note - answers may recommend something you note, but might have overlooked.
4. Give us an enumerated list of constraints, in order of importance
Every recommendation question probably needs this list. Tell us the features or operating constraints a good fit would meet, ordered from must-have to nice-to-have. An example:
- Must run on OS/2, with 128 MB of RAM
- Must not be pink
- Ideally takes less than 2MB of disk
- Big plus if it plays music
5. Wrap up your question, if it needs wrapping up.
You can probably skip this most of the time if you want, but this is a place to put anything supplemental. It's hard to define that, beyond you'll know it when you encounter it.
Your goal when writing is to narrow the scope enough so that realistically, 10 answers might directly answer it. It's really not too hard and the simple exercise of just writing it all down can sometimes make you think of something you might have overlooked.
That's everything someone needs in order to give you a great recommendation. We may not be able to meet all of your requirements, but since you've listed them in the order of importance, we'll be able to recommend something that gets the most important job done.