How to draw Celtic Knots on a Grid

I've recently got into drawing Celtic Knots and have been using a method I've used for years, adapted from a book I had over twenty years ago. If you know which book it might be, please do let me know because I've forgotten! I do have some recommendations for finding more about Celtic Art. A couple of channels on YouTube; David Nicholls and Aon Celtic Art are both really helpful. I've also been working through Aidan Meehan's 'The Book of Celtic Design' and have found lots of inspiration there. I also have a watercolour celtic knot tutorial over on my other channel: SUPPLIES Pens: I like uni-pin waterproof fine line drawing pens. I use every size from to 0.8 so I buy them in sets of multiple sizes whenever I see an offer on them! This link is an affilia