Suits can be great

Gray plaid suit and red bow tie

This style with the bow tie is somewhat festive. For everyday use in the office one should leave the bow tie out though. Instead, take either a tie or the collar can be left free and you can replace this handkerchief with (matching the shirt) a white one. Through the white shirt you have the liberty to take any tie you want. The shirt is made from 100% cotton and noniron. I find that really good, because ironing is a pure waste of time. The half-length trench coat is suitable for the transitional period, not too hot but warm enough when it’s outside about 14 degrees.