Create a "toy zone" with painter's tape
Some kids like sorting and organizing Legos -- mine don't. They spread Legos all over the kitchen floor while they play which is wonderful...until it's time to clean up or actually use the room as a kitchen.
So my husband created a Toy Zone, marked off with blue painter tape. The kids are free to leave their Lego projects on the floor provided they stay within the boundaries. That leaves the paths through the kitchen and food prep areas free and clear. It's working beautifully!
SMOOCH! (Professionally, of course.) (And an extra one for Darienne who shared the hack with us.)
More: Hacks involving Legos (organizing them, cleaning them up, building stuff with them...)