Step 3a:  Solve Two Adjacent Edges

This is another intuitive step.  The only "alg" I use here is (0,-1) / (1,1) / (-1,0).  This will swap UF with DB and UB with DF; in other words, those four edges criss-cross with each other.  By using this move, you can very easily solve two adjacent edges in the bottom layer, just make sure that you don't disturb edges that are already solved.