Usually, I run Chrome, Steam and Slack as my main. Lately, I use HWMonitor to keep an eye on the temperature.
In tray I have Dropbox, Killer Network Manager, StellSeries Engine (for mouse), AlienFX (because of Alienware stuff), SB Recon3Di Control Panel (sound), Lightshot (for screenshots), TESORO Keyboard (for keyboard), Intel RST (for HDD and SSD, as I may see) and f.lux. Sometimes I run Photoshop or Flash, or play some games, but trying to keep less apps running on the same time (but even in that case I usually have no problems with the memory, only downloads make everything so bad)
For "Clean Boot" - you mean that method, when in msconfig I turn off all services,that are not MS and then reboot?