1. Material: Genuine leather is the most common and recommended material for formal office shoes. It is durable, breathable, and has a polished appearance that adds a professional touch to your overall attire.

2. Style: Look for a classic and timeless style such as oxford, derby, or loafers, as these are considered appropriate for formal office wear. They typically have a closed toe, a low heel, and a lace-up or slip-on design.

3. Fit: Comfortable office shoes should have a proper fit to ensure maximum comfort throughout the day. It's important to measure your feet accurately and choose the right size. Shoes that are too tight or too loose can cause discomfort and pain.

4. Cushioning and Arch Support: Good quality formal shoes should have ample cushioning and arch support to provide comfort during long hours of standing or walking in the office. Look for shoes with padded insoles or memory foam for added comfort.

5. Sole: A rubber or leather sole with a non-slip grip is ideal for office shoes, as it provides stability and prevents slipping on smooth office floors. A flexible sole allows for natural foot movement and reduces strain on the feet.

6. Breathability: Proper ventilation is important for comfort during long office hours. Look for shoes with breathable lining or perforations that allow air circulation, keeping your feet fresh and dry.

7. Heel Height: For maximum comfort, opt for shoes with a low heel or no heel at all. High heels can cause discomfort and strain on the feet and should be avoided for daily office wear.

8. Brand and Quality: Choose shoes from reputable brands known for their quality craftsmanship and durability. Investing in a good pair of leather formal shoes may cost more upfront, but it's worth it for long-term comfort and durability.

9. Break-in Period: Keep in mind that leather shoes may require a short break-in period to mold to the shape of your feet. It's important to wear them gradually and not for long hours initially to allow them to adjust to your feet.

By considering these details, you can find leather formal shoes that are not only stylish but also comfortable for daily office wear. It's always a good idea to try on the shoes and walk around in them to ensure they fit well and feel comfortable before making a purchase.