Roll out the dough for your top crust to about a 12" circle (less than 1/4" thick).
Using a straight or fluted pastry cutter (or other cutting tool), cut out strips of desired widths from your rolled out pie crust. You'll need about 10-12 for a standard 9" pie.
Starting in the middle, transfer every other strip of dough and lay them parallel to each other on top of your filling, at whatever spacing you want.
Turn back every other strip of dough a little more than halfway, then take the longest strip left of the ones you cut out and lay it perpendicularly across the top of the pie on the strips not turned back.
Straighten out the turned-back strips and turn back strips you didn't touch the first time. Lay the next smallest piece of rolled out strip next to the first perpendicular piece.
Repeat alternating turning-back the parallel strips to finish the current side, then turn the pie around and repeat the process for the other side.
Once the strips are woven, crimp the edge of the lower crust onto the ends of the strips to seal them.
Brush the top of the lattice with an egg wash to get that golden color pies deserve.