Running program on startup (Fedora 22/ 2015)

I tried really hard to avoid posting a new question for something so basic and already answered in a hundred places, but after spending two hours on this and trying every solution out there I’m thinking they’re either outdated or don’t apply to the current version of Fedora.

What I tried (among other things):

• gnome-session-properties (doesn’t exist anymore)
• gnome-tweak-tool (can only add existing applications to startup, ie: can’t add custom commands)
• my working .sh script in ~/.config/autostart (chmodded executable)
• .desktop file in ~/.config/autostart
• script in rc.local (this appears to be ignored now)
• script in /etc/init.d(chmodded executable with sudo)

The above all fail to run my script on start up.

The script I’m trying to run:

#!/bin/sh
xcompmgr

Or even simply this command:

xcompmgr

My exact setup:

Fedora 22
Kernel 4.0.4
Gnome shell 3.16.2
Awesome WM 3.5.6

Sorry for the repetitive question, but I’m throwing the towel. What is the simplest, up-to-date way of running a command or script on start up on my setup?