The above video depicts how to increase evenly with one stitch on either side of the work. Do as follows:

Step One – Insert hook into top horizontal bar between edge and 1st inside vertical bar.

Step Two – Yarn over and pull up a loop. One increase made.

Step Three – Work remaining stitches, with the except of the edge stitch, per usual.

Step Four – Insert hook into top horizontal bar between 2nd to last vertical bar and the end-edge loop.

Step Five – Yarn over and pull up a loop. One increase made.

Step Six – Complete forward pass by inserting hook into the end-edge loop, and the back loop behind it.

Step Seven – Yarn over and pull up a loop. Forward pass increase row complete.