Read to them as well as asking them to sound out particular words. Ask them to sound out words they might see when you're together - where to park for instance.
I like to read a couple of pages and then I ask my child to read a sentence or two.
Or we look at one particular word and see if we can find it in the rest of the book. The Biff and Chip series have the same word throughout each page. I try and embed the word doing another activity i.e. 'oa' sound - boat, moat, float. We'd read the book going over the sound and then do an activity like making a boat and seeing it float 😀
Keep up reading with them, ask them to read a cake recipe and then make the cake, you'll keep them on task and give them a chance to engage in messy play with you by their side