How con you use modge pod on glass without leaving streaks?

I find using a sponge style paint brush works the best. Hope this helps.

Water it down a tad and use sponge brush. A little goes a long way.

Try Liquitex gloss medium and varnish. It’s in the art section at your craft store. Very durable and dries clear. Also comes in flat.

I have lots of experience working on glass doing decoupage. First of all you put the glue (I use Elmers) on the image, although it is not "wrong" to put it on the glass. After the image is positioned as you like it, you must wash the glue off the rest of the glass. I just do this holding the piece over the sink. . . and if any residue remains I use windex to clean it off. Remember if you are working on glass your work is on the BACK of the glass!