Since API change we can't track our own HoTs and DoTs so I came up with idea of timer addon. How it works:
In addon settings you manually set timer for abilities that have HoT, DoT or other temporary effects.
Then you set hotkeys for timers (same keys as your skills) so they will activate at the same time.
Once you finish setup, this addon will show little countdown timers above skill icons so you can track your own buffs and debuffs duration. For the skills in the second action bar, countdown timers could be a little above timers of 1st skill bar. Or maybe it's even possible to position timers on skill icons?
you press skill hotkey -> countdown timer start
if you activate skill while timer is active -> timer resets and start again
if countdown reach 0 -> timer fade out