As Microsoft have now unveiled the CPP of Windows Vista Beta 2 I thought it would be a good time for some tips.
Firstly, the boot loader is brand new, it has no GUI at the moment and can only be edited via the command prompt - no it's not in plain text either. So you may want to install on a separate drive with the boot order controlled by the BIOS - just encase.
Secondly... UAP getting you down? You can disable it by Start -> msconfig -> Tools -> Run disable UAP. I'd recommend enabling it again once you've finished installing everything.
Thirdly... The search indexer can be annoying at times, if you're like me and know where you keep all your documents you can disable it at Control Panel -> Admin Tools -> Services -> Windows Search. Change it to disabled or stopped. I don't recommend disabling it in the final version as other applications will depend on the indexer being active.
Fourthly, make use of the error reporting tools, they're much improved over Windows XP - and you do actually get feedback for problems. For me Vista went and found a patch that made Halo work... Now that's pretty cool.
Finally, keep in mind this is a beta, and it's very beta too. It's pretty solid for me but it does have its bugs and many of them.