Good question. There is no right or wrong size for art, it is purely based on the space you are putting the piece in. The image below shows the paper sizes (A4, A3, and A2) in situ above a cot. The frames have a window mount, which adds a little space between the artwork and the frame. You can use this type of framing to make an artwork take up more space.
Picking a frame to match your new artwork is part of the fun - it can be a great opportunity to show off your creative flair. White and Oak frames generally suit all artworks, whereas black frames can sometimes clash with an artwork if it is particularly colourful. We recommend taking a look at the space you want to put the artwork in and basing your decision off the rest of the room.
Of course! Mixing frames styles and colours can add an eclectic vibrancy to a space without much effort. If you are interested in being playful with your frame choice, we recommend taking your artwork to a professional framer. If you want some framing tips, feel free to send us a photo of your space to firstname.lastname@example.org