The Initial Design
Much of this stems from how you design the office in the first place when it is being either built or decorated. You need to make sure that you are putting a lot of effort into how it looks, to ensure that it is going to appear as professional as possible. There are many details which can help to make your office look how people would expect a professional office to look, and as long as you are focused on those details, you should find that that is what you have. The simple installation of made to measure aluminium windows can make a surprising difference to how professional a place looks, as can the style of the carpet and lighting, and even the way the walls are decorated. Consider all of this in the initial design if you want the space to look professional.
You might be surprised to hear that a lot can also be conveyed by how the office is laid out too, and that is worth looking into if you want to make sure that you are providing a space which as professional as you would hope it to be. You need to ensure that people walking into the office and seeing the way it is laid out will think to themselves that it is a respectable space, and the best test for that is to be honest with yourself and ask yourself whether that is currently the case. If it is, you will know that others are probably looking upon in it the same way too. It is okay to have some informality, so long as you also have a professional layout overall.
Finally it’s important to remember the value that different colors can have when it comes to making your office look as professional as possible. In general, you will want to stick to fairly neutral pastel colors, and not anything too colorful or bright. But that doesn’t mean that the occasional splash of color can’t help either, and it is something you might want to consider if you are trying to achieve the most professional look you possibly can.