A and E, my 7 and 5 year olds, have long enjoyed leggo play, but until recently, their play has been fairly free-form, involving constructing castles of the imagination rather than trying to build defined structures or follow instructions. Just lately, though, A in particular has expressed interest in trying to build leggo creations following the instructions. She really, really wanted to have a go at building a complex car / truck thing that we'd been given some time ago, which involved a thick instruction book, had an age-rating of 9 and up, and had many, many tiny little parts.
I nodded brightly when she expressed this interest, then suggested that this might be a Daddy and girls project!
So my husband and the big girls have now logged three 2-hr sessions of truck-building, following detailed instructions, working together, nutting out complicated bits, rebuilding where necessary. I've used these times (mostly Sunday afternoons) to log some paid work time while the toddler has napped. The girls have hugely enjoyed having concentrated time with their Dad and doing something so sustained and involved. (In that regard it's resembled a holiday project I do each school hols with the kids - putting together a 500 or 1,000 piece puzzle over several sessions of working together).