M1L without holes

[faffadoodledo]

I’ve managed to confuddle myself quite thoroughly. What’s the best way to make a left leaning increase (mid row) without leaving a hole? Bonus points if you can link to a shirt and sweet video.
I’ve done this dozens of times but keep getting it wrong!

There are some videos on this. But pick up the bar between the stitche (with front of bar in front) and then knit into the back of it. If you don't knit into the back it will make a hole.

Take a look at Nimble Needles here: