For me it depends on the pattern, like for a 4 patch, I place all the blocks for the quilt on the floor, then pick up the blocks from the top down, placing them on top of each block.
At the bottom I write a row number and pin it together. When I have all the rows I start strip piecing, row 2 onto row 1, and row 3 to row 2 until all the rows are done, then after I press it I sew across.
But on others such as Garden Twist, I start at a corner and piece diagonal.