The way you configure your primary browser effects the way you see the web. Using a suite of browsers during your test rounds is one thing, but it's not the same as using a particular browser and configuration on a daily basis.
- Set your system/browser's default background to something other than white
- Disable plugins by default (enable them on demand)
- Disable meta refresh
These three tips will catch a huge number of sites which make assumptions about browsers. The errors you catch with these settings aren't necessarily the end of the world, but they are a sort of litmus test for site build quality. Plus, many sites do in fact fail completely under these simple-sounding conditions.
On a Windows PC (not sure about Macs), a web page with no explicitly stated background colour will be rendered with the Windows default background colour. Since the default Windows background is white, many developers forget to actually set the background when they want it to be white. However to reduce eye strain I set the Windows background to a light grey or off white, so I get to see which sites haven't set a background colour.
It really is quite astonishing how many sites don't actually set their white backgrounds! There are some very popular sites (by large companies) and even a couple of A list bloggers who have forgotten this one.
While it's not the worst error out there, it can certainly be a problem if a user has a black system background and you've got black text. I know someone who has grey on black as their system default; and they regularly have to highlight websites just to read them.
I think Firefox has started overriding the system background and inserting white as a default, but that's not really a solution.
To change your Windows background: click Start → Settings → Control Panel → Display → Appearance → Advanced. Click on the diagram or select Window from the Item dropdown. Change that item's colour and apply the change.
[If someone knows the MacOS equivalent to change the default background in web browsers, feel free to comment or let me know :)]
You should regularly browse with plugins disabled. It's interesting to see how many sites use flash for critical content yet have no fallback at all. Many all-Flash sites don't even have a warning message telling you to install Flash - they just load as a blank screen.
I use Opera and go a bit further, disabling animated graphics and Java. It's trivially simple to switch them back on a for a site, so why not. With Opera's site preferences I can enable plugins for those few sites where I do want the plugins to work (eg. YouTube). To toggle these settings, use the Quick Preferences menu to disable plugins then use Edit Site Preferences to enable them for chosen sites.
I'm not sure if Firefox can disable plugins once they are installed, however there are various extensions (eg. Flashblock) which can disable Flash. It's buried in IE as well but to be honest I don't recommend using IE as your daily browser anyway - it encourages complacency, since you don't notice all the sites out there that don't work in anything other than IE.
disable meta refresh
Meta refresh is particularly problematic for users with screen readers, since the uncontrolled refreshes create confusing and unpredictable experiences. For this and many other reasons, browsers are now making it a lot easier to block meta refreshes.
The thing is, many sites use these to forward the user from one page to another - but they don't include a manual, clickable link. Many people assumed that browsers would never be able to switch off refreshes I guess!
To disable meta refresh:
- Opera: browse to opera:config#UserPrefs|ClientRefresh, then deselect the option and restart Opera.
- Firefox: you can wait for version three, or install the Web Developer's Toolbar and click Disable → Disable Meta Redirects.
- In Internet Explorer: go to Tools → Internet options → Security tab → Custom Level button → Miscellaneous category → set "Allow META REFRESH" to Disable.
[Feel free to comment if you know instructions for other browsers.]
...and that's it
These tips should help remind you to provide fallback content if you're using plugins, scripts or modifying standard page load behaviour in any way. If nothing else, it should remind you that white backgrounds don't magically happen :)