The best way to go formal easily is to wear black. You can add shimmer by way of accessories. Here I am wearing a long black lawn pakistani kurta with black pyjama pants. To add a hint of shimmer ,I have worn silver chappals and a pure silver necklace with orange beads. The kurta and pyjamas along with the slippers cost around INR 3500.
The silver necklace is for around INR4000 picked up from an exhibition. I wore this to a club. It was an informal dinner with friends.
Hope you like the look!
( Excuse the picture quality)