I've been asked to revisit my tangle 'Adeline'. It's based on a carving I saw in a picture so I didn't invent it - I've just figured out the steps and gave it a name. (In honor of my mom.) It's a bit more intricate than some of my other tangles so take your time and practice it on scrap paper a couple of times.
These are all the steps together if you want to do a 'copy and paste' and print out a copy for yourself. Read on for more detailed instructions.
Begin with evenly spaced slash marks. Don't make your slash marks too close together (You will see why later in step 5).
Draw double 's' curves. Use your slash marks as a bridge to go over and then as a bridge to 'go under'. Pay attention to which line goes on the top of the s curves and which lines go under the s curves.
Complete the s curves that intertwine with the first set.
Add little balls (ornamentation) where the lines cross.
Add linework to show where the s curves curl when they cross each other. (This is a little fussy and you can skip this step if you wish)
Add shading to complete.