How can I add new autostart programs in Lubuntu?

In Lubuntu, there's no 'Add New Program...' button in Desktop Session Settings. Is there an easy way to add new autostart programs in Lubuntu?

For Lubuntu 11.10 / 12.04 / 12.10 / 13.04 / 14.04 / 14.10 / 16.04

Open the file manager (by default PCManFM), go to /usr/share/applications. Right-click on the program you want to be added to your autostart programs, and click Copy. Now, go to ~/.config/autostart in PCManFM, right-click and click Paste. The program should be added to your autostart programs now, but double-check by clicking the LXMenu down left, click Settings, and then Desktop Session Settings.

You may have to create the autostart folder. For an application that doesn't have a *.desktop file in /usr/share/applications you may also copy-paste any other *.desktop then update it with content suitable for your app.