There are always different ways, but I'd suggest you try a few, stick at them for a few weeks before moving on to the next. Strategies work as a one off, a day, a week, for ever or even never!
What do they like reading? Remember reading is supposed to be fun and enjoyable. It's still reading even if it's not a book. There's are multitudes of online books (tablet/ ipad/ mobile) and a lot of them have a trial period.
From TV guides to magazines, the back of a cereal box. Bringing in rewards, not always financial (save those for your bigger challenges!) But extra time - outside, on a game, going out on the park etc. Let them bank it. Set a challenge of so many pages per day, week etc. Reading plus is used by schools and give a word count for how much they have read.
Visit your local Library and read with and to your children.
If you can, draw pictures with them that suite the part of the story you're reading about. Or dress up from the scenes (this may need a bit of planning ahead!)
But always try not to force them, as this can put them off for a long time.