Office decorating...

I have a ton of wall space in my office and have no clue what to put on it. When I first moved in I was all excited about finding the perfect art work for the walls, and would always get jealous when co-works would come in with the perfect art work for their walls. But as time passed and work got busy, my walls were totally neglected. I broke down over the holidays and bought these. And just got them hung up yesterday! So my quest for office art work is back on. Here's my dilemma though. I don't want to spend a ton of money becausem, its my office, and who knows how long I will have the same office. Also the walls in my office are a beige color not white, so I am a bit limited with the type of colors I can choose, and the furniture is all earth tones. I went on etsy to see if there where any cool prints and I found a few that might work to do in a series of three. I would probably matte and frame all of them to give them a little bit of uniform look. Let me know what you think and if you have more suggestions, I am all ears! I never thought decorating an office would be so troublesome. I had so much fun decorating my house, and thought this would be fun too, but it has turned into somewhat of a burden. I want my office to feel warm and inviting, but also somewhat professional...please help!!