Hmm, in Windows Phones, one basically gets what he sees. There are no real performance/tuning tricks that will push the phone beyond it's normal capabilities, though there are tips (a lot of them) to increase/prolong battery life. But with respect to performance, you could try disabling battery saver though it's uncertain if that has any effect on processor throttling if processor throttling is even implemented in Windows Phones.
There has been a partially technical discussion on how Windows Phones "manage" memory usage, but the bottom line is that Windows Phones are efficient at handling and allocating memory, but if it would satisfy one's curiosity one could:
1. Avoid switching apps into the background, e.g. without closing them;
2. Prevent unnecessary apps from running in the background;
3. Avoid pinning too many tiles in the start screen;
4. Avoid installing too many apps in the phone.
Among these options, I've only had a problem with #2, where a lot of apps simultaneously updating their live tiles seems to cause the start screen to stutter a bit. #4 seems to affect how fast the phone starts up and shuts down. As for # 1 and #3, I've seen no conclusive effects.
Unlike older versions of Windows Mobile devices (Windows Mobile 6.5.3 and below) where processor overclocking, processor tuning, and other "hacks" are available, those hacks and tricks are simply not available in current Windows Phones.