I've made a bunch of videos for Decal[1] - and whilst I'm still on a long learning process I can probably give you a few bits of advice:

1. For initial marketing/landing videos don't spend too long showing the actual product - don't try and pack in a complete feature demonstration in. You only need to get people just interested enough that they'll try the product out - you can have a longer, more detailed instructional video as part of the initial sign-in/login process (still - you should keep your instructional videos under 5 minutes, preferably 3 minutes if you can).

2. When I did a landing video that was 3 minutes, average watched was 73% according to Wistia's stats - when I did a landing video that was 60 seconds average watched was 98%

3. Background music is useful for marketing/landing pages, but not for instructional videos

4. If you're doing an instructional video, it's good to have pauses in screen movement from time to time - it's hard to process information about what's happening on the screen simultaneously whilst listening to the audio so you need to give the brain some time to catch up (even if the words are describing what's happening on the screen)

5. ScreenFlow is awesome

6. You can improve the quality of your voice over without shelling out for an expensive mic by sitting in a closet (compare the V.O quality on the first round of Decal marketing videos I did with this one that's about to be released: http://iain.wistia.com/m/Ki1dVy - NB: still vascillating on the backing track for that one)

7. If you want to really hammer home a message, put words on the screen that are keywords from the voice over. It's a powerful way to get the message to stick in people's minds.

8. I've experimented with a "straight to camera" video piece - it's hard to look good. You need a proper lighting setup, otherwise you end up looking like an al-qaeda suicide bomber. That being said, however, having a straight to camera piece seemed to improve people's tolerance for a very rapid product overview.

9. Start the video with a statement - try to orientate people and give them a context for where they are and what you're trying to achieve. In the case of instructional videos, you can say something like "This video is intended as a fast paced overview of all available features. For more detailed instructions see our support page" or something. For marketing videos start with the key benefit - try to get that out in the first 10 - 15 seconds.

10. Using Wistia for video hosting is great because you get good stats, a range of embed options including the cool "post roll call to action" which prompts people to click a link when the video finishes and no brand dilution (ie. people don't see youtube ads or get prompted to leave your product and view something else when the video finishes).

11. Marketing video takes way longer than instructional video to create because of the editing process. The process I go through for Marketing vids is:

- Write copy first, time yourself speaking it, get it under 1 minute

- Record a rough draft of you speaking the copy

- Story board the video - I use index cards or a whiteboard for this - ie. "When I'm saying this, I should see this on the screen"

- Record and edit the video to the draft V.O - make sure you cut out unnecessary loading times or mouse movements and use transitions and screen zooms to help ease the rapid pace of action on screen and focus people's attention

- Do the final reading (in the closet or sound proofed room :) and then cut that up, cut out any "smacking" noises or breathing when editing, and place that to the video

- Now decide on a sound track, try a few options and see what's best. I'm vascillating on my choice of the Mbira for the Decal Mockups launch vid because it's kind of strange and I fear people will spend too long trying to figure out what the hell that music is, and lose focus on the video. Here's another version with (coincidentally) Adrian Holovaty playing a Gypsy Jazz version of "all of me" http://iain.wistia.com/m/xP1dqp - I think that's better (I haven't asked Adrian's permission to use it yet, though :)

For instructional videos my process is slightly different:

- Just use the product, go through basically the way that I would demo it to someone if I was showing it to them, and record this

- Then edit the video down to about 3 or 4 minutes - if it's too dense, separate subject matter into separate videos and reference them on a support page

- Now that you have your "demo framework" simply narrate that - write down your narration, then record this as a draft voice over

- Now go back and, for each section of narration, record the video for that again, specifically to go with that narration. You'll be more focused and get a better result with less choppy mouse edits

- Now go sit in the closet again and do the V.O and edit that down to fit the video

I think that's about it. I'm by no means a professional but I've been hacking away at it for a while so hopefully some of this is helpful to you.

1. http://www.decalcms.com/