When I saw zills being used, I set about obtaining them. We are lucky to have a great Drumming Group for live music on the coast, so I sat against the wall for many months during their practise sessions and learnt the various drum rythmns. When I could zill those fascinating beats and also in the gaps between the beats, I played with the group and also at hafflas. That fun continued for 6 years, until arthritis made it too painful.
Now playing them is only now and again. There is a little trick to pass on.......
you can make up a short phrase, eg.little bird why not fly fly fly.. and zill out that rythm, as you silently repeat the words. That's useful if there are a group zilling together. Good luck!