Tutorial here. Please note that you can either use edges or sketches to define the direction of patterns. You can pattern almost any feature, they don't have the be "merged" with the original feature.
Start by creating a sample extrude
Sketch and position your feature which you will be patterning later.
After creating the feature, open the "linear pattern" feature
Select one of the edges as the direction and then select the extruded cut as the feature to pattern.
Sometimes you have to have 2 rows, so select the perpendicular edge to create a pattern that goes sideways aswell.
Great work :)