Since you are asking for "secure" harness advice, I am assuming you are looking for somethign escape proof. I live on a pretty busy street right outside of NYC, so this was really critical for me also.
These are a few I like:
These are a few I like:
- Lunine Roman Harness. Pro: Very secure. Con: A little bit of a hassle to take off if you have the neck adjusted fairly close. There are multiple options, including reflective and holiday. If yo take photos in the park, the harness doesn't overpower the photo. They have cute prints. MicroBatch Roman Dog Harness
- Bond and Co harness from Petco. They have several colors. They are mesh and comfortable and easy to take on and off. Very secure. XS/S fits our little ones and it's the only size. Other colors include black, red, and light blue. https://www.petco.com/shop/en/petcostore/product/bond-and-co-reflective-pink-mesh-dog-harness
- Buddy Belts. I have one on order. I have not used it yet. I am getting it because it will be easy to take on and off, won't overpower photos, and is escape proof. I have friends who use this harness. BUDDY BELTS Classic Leather Back Clip Dog Harness, Premium Caramel, Size 4: 14 to 16-in chest - Chewy.com