It's the first law of movie-making: no matter how expensive your camera, or how skilled you are at using it, your raw footage will always be rubbish. And so, if you're looking to add a little professional polish, then installing a video editor will be essential.

Commercial video editors can be very expensive, of course, but you may not have to go that far. Whether you want to trim your clips down to size, add a soundtrack or captions, apply transitions or special effects, there are some great free tools which can help - and these are the very best around.

1. Windows Movie Maker 2012

Download Windows Movie Maker 2012

Windows Movie Maker is supremely easy to use. Just drag and drop a few clips onto the program (most formats are supported) and immediately they're assembled into order; transitions and special effects are just a click away.

Windows Movie Maker

It's just as simple to add a soundtrack, captions and credits, and you can save the results as a video file, or upload them directly to YouTube, Facebook and many other sites.

You can take a little more control when you need it, for instance trimming clips and applying a few other basic options. The program's main focus is on making it very simple to produce quality movies, though, and for the most part it's a great success.

------------------------------------------------------------------------------------------------

2. Kate's Video Toolkit

Download Kate's Video Toolkit

While there's nothing too surprising in Kate's Video Toolkit, it does provide some basic but useful editing features. So you can trim files or join them, link two videos with a transition, create a sequence of videos with a custom soundtrack, and there's a simple file format conversion tool as well.

Kates Video Toolkit

There are plenty of limitations, too (you can't maximise the program window to use your full screen resolution, for instance), but Kate's Video Toolkit is extremely easy to use. If you don't want to read Help files and your editing needs are simple, it could be a great choice.

------------------------------------------------------------------------------------------------

3. Avidemux

Download Avidemux

Avidemux is a small but capable open source video editor which can help you join clips, cut them (without re-encoding), and apply a lengthy list of useful filters (Add Logo, Crop, Flip, Rotate, Resize, Sharpen, Remove Noise, tweak brightness, contrast colours and more).

Avidemux

While this sounds basic, there are lots of options and fine controls to help make sure everything goes as you expect, and an excellent online wiki which documents everything. Overall, Avidemux is well worth a look, as long as you're happy to spend a little time learning how it all works.

------------------------------------------------------------------------------------------------

4. VSDC Free Video Editor

Download VSDC Free Video Editor

Non-linear video editors can take some time to learn, and VSDC Free Video Editor is no exception (a lack of useful documentation doesn't help, either).

If you persevere, though, you'll find a capable editor with plenty of functionality: drawing and selection tools, plenty of colour and lighting corrections, some useful filters, transitions, audio effects and more.

VSDC Free Video Editor

When your project is complete, there are options to save it to file, optimise your movie for various mobile devices, or even burn it to DVD.

------------------------------------------------------------------------------------------------

5. MPEG Streamclip 1.2.1b6

Download MPEG Streamclip 1.2.1b6

With a download size of only 327KB, you'd expect MPEG Streamclip to be, well, a little underpowered. And yet, the program opens multiple files, DVDs or URLs of video streams; can trim, cut, copy or paste parts of your footage; and has options to rotate your footage or export the soundtrack, while its Export dialog provides more control over your finished video than some commercial products.

MPEG Streamclip

It's not all good news - we had problems playing back some MP4 files - but if you're just looking for trimming and file conversion features then MPEG Streamclip is definitely worth a try.