When given information about the OC, I was told the OC has a blue checked scarf so I used this as a reference:
One Trick also told me that this character had a Norse theme going on with her and requested that her Cutie Mark be Freyja's Brísingamen necklace. Since there was a lot of different necklace designs for the Brísingamen online, we more or less chose the one that was the least complicated and easiest to translate to a cartoony style.
They both also gave me these pictures for additional references:
They also requested to make her a little bit chubby, so I looked at some pictures of the ponies on the show for reference and tried making her slightly chubbier compared to the main pony body type used in the show. I also looked up a few pictures of ponies sitting down in the show for additional reference too.
When drawing her lower half, I decided to give her tail a braid to match the ones on her mane.