A couple of variations of knotted crosses, done with the cobra stitch/Solomon bar/Portuguese sinnet, using 1.4mm cord.
You first tie a complete vertical section, leaving a little bit of space/slack where arm section will go, then tie the second section with the cords going thru the space left in the first part.
The larger one is about 4.5 inches tall by 3 inches wide(not counting the loop at the top). The smaller is about 2 inches tall by 1.5 inches wide. You could use fabric glue or super glue to stiffen it up if desired.
I've seen at least a couple similar examples of these online, made with rope/twine and paracord. I'll add the links if I can find them again, or if someone has the links, maybe they can add them in the comments section. Found one here, though it's not one of the previous one's I've seen before, similar nonetheless.
They can also be tied like the round/square sinnets, by working two separate sinnets towards each other. Either the top and bottom first and outward to do the arms or arms first, then top and bottom sections. I have tried it this way and it was decidedly more complicated than I thought it needed to be, so I just went with the easier method of two separated sections. YMMV