You do not need to be a pro photographer or great at Photoshop to create wall art that represents your style, especially when posters can be rather expensive.
Two easy ways to make your own art is with beautiful post cards, especially vintage ones that are timeless or another underestimated kind of art : gift wrap paper.
Of course, seasonal gift wrap is better to be avoided unless it’s the look your are going for. Simple, neutral gift wrap paper is very inexpensive, can be cut to fit any frame size. Also it can be used as a background for your photography and be changed as often as you wish.