What do you guys recommend/use for first layer settings for PLA in S3D?

I am getting a little bit of incomplete lay down of the material - gaps etc on the first layer. I thought bed level but I am not sure.

I increased the extrusion multiplier from 90 to 95 and it helped a lot but it also made the subsequent final layers much "rougher" when compared to the same piece printed at 90 which prints really great. My thinking is I need to address only the first layer and not all layers. Does this make sense?