Its hard but quite easy to achieve that balance of casual yet put together. Whether you keep the outfit simple and add in sprucing accessories or keep the outfit prim but scale down the add-ons.
Here are some of my favorite ways to do both of those:
Simplicity in Details: I love a good anorak but this one by Topshop has a cute camo sequin detailing on the shoulders, chest, and back. With that boyfriend loose fit paired with denim joggers, a cute shirt, and an easy pair of sneakers, its still comfy yet stylish. Easy going without being a try hard.
Jacket: Topshop Camo Sequin Shirt Jacket
T-Shirt: Uniqlo Pixar Graphic Tee
Pants: GAP 1969 Denim Joggers
Shoes: Vince 'Blair 5' Leather Sneakers
T-Shirt: J. Crew Tissue T-shirt
Shoes: Isabel Marant Bart Sneakers
Jacket: BLANKNYC Suede Moto Jacket
Jeans: Citizens of Humanity Emerson BF Jeans
Of course some cute accessories that can jazz it up or down would be these bad gyals.
Mansur Gavriel Mini Bucket Bag
J. Crew Mini Rider
Proenza Schouler Tiny Fringed Shoulder Bag