A long-sleeved shirt is generally ok, but its veering into too formal if its a fancier shirt
The best casual sundresses usually have a few things in common: enough structure to skim the body, fabric that does not cling, a neckline that draws the eye upward, and a length that feels comfortable when you sit, walk, or bend over to pick up your purse because somehow it always falls off the chair
As such, I've divided this black dress styling guide into two parts

Spaghetti Strap Bodycon Dress Filters clothes size colour product type No results found style shop by figure Sort: Relevance sale Sand Slinky Asymmetric Twisted Strap Maxi Dress #Maxi #Asymmetric #Spaghetti Strap $14.50 $73.00 -80% Chocolate Woven Pleated Hem Detail Spaghetti Maxi Dress #Plain #Maxi #Spaghetti Strap $104.00 sale Nude Textured Effect Spaghetti Strap Bodycon Dress #Plain #Mini $21.00 $105.00 -80% Blue Rib Contrast Binding Spaghetti Strap Mini Dress #Plain #Mini #Spaghetti Strap $47.00 Chocolate Polka Dot Contrast Spaghetti Strap Mini Dress #Mini #Spaghetti Strap $45.00 Brown Rib Contrast Binding Spaghetti Strap Mini Dress #Mini #Straight Neck #Spaghetti Strap $47.00 sale Cherry Red Faux Leather Spaghetti Strap Midi Dress #Plain #Midi #Scoop $18.50 $57.00 -68% Cream Satin Spaghetti Strap Contrast Cup Mini Dress #Mini #Scoop #Spaghetti Strap $73.00 sale Black Lace Spaghetti Strap Mini Shift Dress #Plain #Mini #Scoop $20.00 $68.00 -71% sale Chocolate Brown Slinky Twisted Strap Ruched Seam Bodycon Dress #Plain #Mini #Asymmetric $22.00 $57.00 -61% Shape Brown Satin Twist Strap Mini Bodycon #Plain #Mini #Spaghetti Strap $57.00 Stone Contrast Lace Wrap Spaghetti Strap Mini Dress #Plain #Cowl #Bandeau $68.00 sale Black Textured Knot Strap Detail Maxi Dress #Plain #Maxi #Scoop $17.00 $73.00 -77% sale Taupe Textured Knot Strap Detail Maxi Dress #Plain #Maxi #Scoop $17.00 $73.00 -77% Cream Textured Fringe Tassel Hem Bodycon Dress #Plain #Scoop #Spaghetti Strap $91.00 Orange Textured Beaded Strappy Bodycon Dress #Mini #Scoop #Spaghetti Strap $34.00 sale Stone Sequin Strappy Bodycon Dress #Plain #Straight Neck #Spaghetti Strap $46.00 $130.00 -65% Cream Textured Strappy Scoop Neck Sleeveless Bodycon Dress #Plain #Mini #Scoop $24.00 sale Dusty Blue Slinky Strappy Bodycon Dress #Plain #Mini #Scoop $14.00 $32.00 -56% Cream Textured Beaded Strappy Bodycon Dress #Plain #Scoop #Spaghetti Strap $47.00 Yellow Sequin One Shoulder Strappy Bodycon Dress #Plain #Mini #One Shoulder $73.00 sale Plus Plus Lime Satin Scarf Detail Bodycon Dress #Plain #Halterneck #Spaghetti Strap $26.00 $52.00 -50% Black Textured Boat Neck Sleeveless Bodycon Dress #Plain #Mini #Spaghetti Strap $39.00 sale Slate Grey Slinky Ruched Seam Bodycon Dress #Plain #Mini #Halterneck $22.00 $57.00 -61% Showing 24 of 242

Sleeveless in style, the gown allows for ease of movement and showcases the shoulders and arms
Clues: Does the invitation say semi-formal wear or cocktail attire