There is definitely some trial and error involved in determining the right style of embroidery to sit well in the knit, but spend some time knitting up some different swatches to see what works best for you.
Another important detail to consider is the stabilizer - this will also take some experimentation to get the look you are trying to achieve. The right stabilizer will temporarily "stiffen" the fabric to hold it taut as the machine does it's work.
There are a variety of stabilizers available with a variety of purposes and uses. Some are used below the fabric you are embroidering. Some are used on the top. Water soluble and Heat Away are commonly used as a top side stabilizer, to really help your embroidery "pop". Water soluble stabilizer will dissolve in water. Heat away turns to ash with the heat of an iron. Either one will leave no trace of the stabilizer but will hold the fabric down to get the job done.
And you if you don't have the fancy equipment, you needn't limit yourself to machine embroidery. Pick up a hoop, a needle, and some embroidery floss to create your own special embroidered touches by hand!
