Some pies, like Strawberry Rhubarb and Cherry, seem to traditionally have a lattice top crust.
There are two ways to criss-cross the top crust.
The easiest is to roll the pie crust and cut it into long strips.
Then simply place some strips going one direction and top them with those going the other direction.
Alternatively, you can weave the top crust, as I'm doing in the photo.
Lightly place the strips going one direction on top of the pie and fold them back half way. Add strips the other direction one at a time, weaving them under and over the other strips.
This is more work and the strips sometimes break, but you can just squeeze them back together. Weaving them makes a bit more elegant presentation.
You can also buy a checkerboard form that acts like a big lattice cookie cutter and will cut the crust into a lattice pattern. This is not as elegant as a woven lattice crust, but the pie will taste just as good!
The finished cherry pie right from the oven: