A neat little thing I found recently. You basically install it and then reboot. On the next boot, it notes everything that ran during the boot, as well as times how long each one took. It then offers help on trimming or delaying certain items that you either don't need at all, or don't need right away.
A neat feature is the delay option. I don't need to be messing about with audio settings as soon as I start up, so I've delayed it. It simply starts up later, when you're idle.
For the recommendations, it's basically crowd sourced. It shows you what other people did and what the general opinion is of a certain item.
Neato ;o