- Cross-site requests not allowed without whitelisting. This means some setup will be required at first (for example, for separate image domains used by Amazon, Google, Yahoo, etc.), but after a bit it shouldn't be a problem. This also serves as a "better adblock" in some ways, as it blocks ad networks without relying on a database that needs to be updated.
- All cookies blocked by default; whitelist as necessary
- JavaScript disabled by default; whitelist-enable as necessary
- No Flash or Java, period. If I need Flash for something, I'll launch a VM.
Sadly, Safari doesn't support whitelisting for any of this. Chrome supports whitelisting of cookies and JS by default, but the Chrome UX is worse than Safari's IMO (for a few reasons, but that's another topic entirely).
RequestPolicy handles the first one quite well, but is unfortunately Firefox-only.