Self-Targeting

So I'm making a modified Invisibility spell for my Night Elven Sniper hero that's supposed to only be able to terget herself. how do I make it so I don't need to tell her to target herself? Is this possible? Or should I use a different ability? Thanks.

Use Windwalk and remove the speed bonus

given, and that's what I'll do, but for reference is there a way to make a spell that normally targets other things target self?

You could use a dummy spell and trigger it, or you will probably have to use the spell with the right effect and set targets to self and range to none, it would force the player to choose the creature casting it but it would be annoying.