This is the second technique you can use to bind off and at the same time drop stitches like you need to with my Drop Dead Gorgeous Loop for example. You can find the first Tutorial on how to bind off drop stitch here.
1. Bind off until the stitch that has to be dropped (drop stitch) is the first/next on your left needle. Knit that drop stitch (and all following stitches, if they have to be dropped as well) and then knit the stitch after that drop stitch(es), too.
2. Slip the stitch you knitted last from your right needle back to the left needle.
3. Now let the drop stitch(es) slip gently from your right needle (they should be next). Try to keep them intact and don’t let them drop the whole way yet. It might help to do that while sitting at a desk that supports the weight of your knitting.
4. Continue to bind off as usual, starting with that slipped stitch. Be careful not to pull out the yarn loop out of the dropped stitch(es). You will do that later.
5. When you finished your bind off, gently pull on the edge so that the dropped stitches will drop and resolve.