Very good to try to blend in with the locals when you go around the parts of the city where/when the locals are around in big numbers.
If you walk near the tourist destinations, even as a local on the way to your work at a time most people around are tourist, you will be seen as a proper target.
When you are between tourists you will be seen as tourist!
Photo by Willeke, may be used under CC rules.
Whatever brand of clothing and accessories you use, as a tourist you are likely to wear/carry them different. No use to spend money on new clothing if as soon as you put them on all locals know you are not from there because you do close that top button (or fail to do so) or an other small detail like that. Better wear something you already own that does not stand out as new or expensive.
You are a tourist, you do touristy things and you will be seen as a tourist, nothing wrong with that.
You might want to avoid places that attract many tourists, as those places also have a lot of people harrassing tourists. But that is as far as you should go.
Better learn the best or most effective way to say "No" to those people. Keep your valuables out of reach, do not inspect what is for sale (or accept when you do that they will aproach you to sell to you) an enjoy being a tourist.
I am not sure what I do to be seen as 'local' in almost all places I travel, not only where my looks fit in (I am a blond Dutch woman) but also where I should stand out because of my looks, like Spain. I usually get asked for the way once a day wherever I travel, but when in Paris or London I am still approached by the sellers of the touristy items.
Wearing well used (but not dirty nor damaged) clothing in which you feel comfortable and self assured, oldworn in backpack or shoulder bag and shoes to walk in (rather than high heels or running shoes) might well help, but even when walking around with my camera at the ready or a map in my hand I am approached as a resident rather than a tourist in many different parts of the world.
By the way, do you rather want to tell someone to get going when you look at a map, or do you want to have your smart phone stolen?
I go for the first, walk around with a paper map when possible and accept being seen as a tourist.
And when I am lost, I look lost, with a map in my hand and most of the time someone really local will ask me whether I need help, which I mostly accept with as much grace as I am able to show.
When you stand in a corner with your phone, people assume you can help yourself and you will miss being told about the great things just around the corner.