Ethically, every program that has autostart capabilities should have an easy to access setting that allows its users to prevent that behavior. Sadly this isn't the case with all software.
For example, I have been working with a client in my 9to5 that uses a software called "Endpoint Security VPN" by Checkpoint which does not provide autostart as an easily configurable setting. Luckily I have a easy solution.
First open up your terminal.
Copy & Paste the following command into your terminal to change it's hidden "autostart" setting.
sudo plutil -replace RunAtLoad -bool NO /Library/LaunchAgents/com.checkpoint.eps.gui.plist
Kill the program so the changes take affect.
pkill -f "Endpoint Security VPN"
Enjoy your reduced boot time!