Use furniture to anchor and ground the look.
No hammer, no problem. Create a gallery wall on existing floating or built in shelves. It makes the look nearly effortless and easy to switch around.
Hang old with new. Absolutely using vintage frames with new modern frames is a-ok. Just the same it's fine to mix a historic print with a portrait of your family or yesterday's beach scene. It gives interest and a cultured look.
Go big. Theres no 'gallery wall rule' that says a specific number is the key so use a large space as the perfect opportunity to go big with your design.
Don't be afraid of color, be bold and embrace hues that you love.
Mix in a mirror to the look to add dimension and depth
now get busy!