Cowl neck sweaters really aren't that boring and there are many ways to pair it up with other clothes. Think of it as a normal t-shirt and see what looks good with it. You could wear it with your favorite skirt (as long as it doesn't clash- and pencil skirts look best with cowl necks.) You could wear it with a nice pair of jeans. If it's a lighter blue, wear dark wash jeans. If it's a darker blue, wear lighter wash jeans. Opposites attract.
I wouldn't wear a lot of jewelry with the sweater. The cowl part of it attracts enough, so maybe a bracelet and a nice pair of earrings will do the trick.
Don't wear regular jogging sneakers with the sweater. It's a bit fancier than other sweaters, so you could wear it with flats or boots or whatever else you want.
I'm sorry if this answer might be a bit late- you could always use it for future reference anyway.
Hi there! (:
For the Navy/Royal Sweater, if I bought it I would wear it with a white scarf over the sweater (wrapped around the neck), denim jeans, dark brown/chocolate leather boots with the jeans tucked in, and put my hair in a low bun. Then maybe some dangling earrings would look cute too. Hopefully that might give you some ideas. You could use any boots, but if you have leather boots, that would look cute. (:
For the Tan Sweater, maybe a colorful scarf over the sweater, or a floral scarf. I actually love scarves. They can make any simple shirt look so much better. Then you could wear jeans, maybe a pair of flats or boots, a pair of earrings and you could leave your hair down. Hopefully the outfit ideas I'm giving you isn't too warm for the weather now since it's spring.
Anyway I hoped I helped, and best of luck! (: