Is there a setting to always start from the home screen on unlock? I am running Lollipop 5.0.2 on an LG phone.  Is there a setting to always start from the home screen on unlock?  Instead of trying to open the last open application.
AOSP ROM doesn't have such setting and neither did I ever hear about such setting in any other ROM. Anyhow, if you are comfortable with app based solutions then you can consider any of the following apps for the objective.

Tasker (7-day trial) does it nicely.


Profile: Event &rarr; Display &rarr; Display Off or Display Unlocked
Task &rarr; Actions: App &rarr; Go Home.


Done!



Macrodroid (free for up to five macros) can also help.

Macro:


Trigger: Screen Unlocked or Screen On/Off &rarr; Screen Off 
Action: Launch Home Screen
Constraints: Choose depending upon the trigger or leave it untouched


Done!



AutomateIt (free) works too.

Rule:


Trigger: Screen Off Trigger or Screen On Trigger
Action: Launch Home Screen Action 
Rule: Show rule popup when launched &rarr; No


Done!



Atooma is also doing well here.


IF: Screen &rarr; Screen On
DO: App Launcher &rarr; choose your launcher app


Done!