I agree that towels can be a serious situation in ME. There are tons of ideas on what to do, and frankly, some are contradictory and some do/don't make sense.
I suspect, and certainly could be wrong, that you have a tension issues. Loops are generally a tension issue. Loops sometimes look like a 'nest' on the underside of your design. May I invite you to check my Needles Blog? Towards the bottom, there are test methods for checking tension on your particular machine. If you have any questions, feel free to email me about them.
Take a photo and post it here for this community to look at and make suggestions. You can post it here in the forum or in the "Challenges and Advice" area. The users on this site are so helpful, I am sure we can assist you to have a project you will be proud of.
Pat, The Avid Embroiderer
If you are interested in selling your projects, you can determine your costs and profits quickly with my Spreadsheet.
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If you want to see my pashminas (that I successfully sell retail) check them out here. I also wholesale them.