Viewing their portfolio is the best way.... and as long as they are honest about their role in each project, you can see how good/creative they are.
make friends! I have taken colleagues/competitors out for coffee, and then got to meet them in their offices and see how their equipment works. Of course, I also share my experiences with my equipment, too.
And, sometimes you can take a quick overview of a system in a store that sells it.
Shop around & get references from trusted sources.
(I work on Mac, PC, and previously Amiga, so I can crash anything)
Kiara, can the editor be remote? I would love to chat with you if you're interested. Just shoot me a message.
Unfortunately, there is no absolute way to "test" an editor, just as there is no clear way to test a surgeon before going under the knife. That being said, the best way to enter into a working relationship with an editor is to view reels/portfolios, speak with references, and ask probing questions of your candidates. As some of the the other posts here mention, there are a number of locations to find qualified editors: mosaicHUB, ProductionHub, and Mandy.com for example. On the bright side, non-linear video editing is a "non-destructive" process. That is, as long as you have a copy of the raw media (and enough time), you can start editing from scratch at any point.
Hi Klara, I think you need to define what exactly you're looking for so that all of us here can help direct you to what you want.
Where: Google, craig's list, ask friends who they use for video.
Testing a video editor: Check their reel (that's usually an okay representation of their work but it's only meaningful if you actually know what you're looking at. The best way to test them is to hire them for a small job (10 second video), it's not free but you get a sense of how they work, and if you can work with them.
You could start by searching here on Mosaic Hub. Find candidates that are in video production and ask if they provide post production services. Another good source is Production Hub.
Your next step is to ask for samples of their work that they were the editor on and have them elaborate on the projects. Ask what their involvement was, if they worked independently or with a director. If they have motion graphic ask if they were designed and created by them or did they hire out. You don't want to assume that motion graphics were done by that editor and then find out that it is not included in their rate.
Honestly though you need to determine what your budget is and have that conversation near the beginning. They will need some information before giving a ballpark quote but so much time is wasted because this question comes last. If you are thinking $500 and they see this as a $10,000+ you are just wasting each others time. Same goes for if you know that something will cost 10,000+ and someone tosses out a $500 quote they are probably not going to live up to your expectation. You will get what you pay for though, in both scenarios.
Let me know if you have any other questions.
Just trying to understand. Are you looking for a video editor?