Buyer’s first of all you need to have a clear idea on your project about what you wanted to get it done.
Now, make a clear note about your requirements and if possible try to make a doc about your tasks or attach respective files.
On fiverr there are three types of best sellers, “Level-1” “Level-2” & “Top rated”
If you are looking for a perfect seller, then mention in your request that to contact you only particular seller, so that you can avoid fake sellers. It saves your time mainly!
Now, contact the sellers individually asking them about the “offer” & “time frame”. Pick the best seller who meets to your cost & time frame.