If your phone is rooted, remove google **** (maps, contact sync, calendar sync, bookmark sync, search, picassa, Gmail, YouTube etc) and some HTC crap (htc hub, likes, message upload, smith, and some more) using a script to clean up the ROM. Disable autosync, disable backup & recover with Google, and most important: don't store personal data such as contacts, calendars & docs with Google. Disable background data, disable 'always on' internet, set WiFi sleep policy to 15 min, set screen animations to none, screen brightness to 25-30%, select powersave on, set powersave to kick in at 25% of power and set all email retrieve settings to manual.
Sent from my HTC Incredible S using XDA
Xperia Z C 6603; Stock LB, Root (101 F/W) (Son's)
Xperia Z C 6602; Stock LB, Root (101 F/W) (Wife's)
Moto E XT1022; Stock (Mine)
Nexus 7 (2012); EHNDROIX-V, Root (Son's)
Dell Venue 7 (2013); Stock 4.3, Root (Ours)
Asus TF 101; ARHD, Root (Mom's)
KitKat FAIL! Stick with Jellybean!