I had to get nearly 3 yo DD3 some sandals and 6 yo DS some trainers.
DS was crying and rolling around on the floor in our house, at the mere mention of shopping. He moaned and rolled on seats and general was unhappy at the shoe shop.
But DD screamed and kicked all the time we were in the shop and throughout the quick shoe trying on stage and payment...it was horrible and the looks I had off other customers 
The promised treat in the cafe afterwards was pointless, as DD3 continued to meltdown and scream.
Nothing I do calms either child when they are upset and I am still trying to accept I am offically a bad parent to DS (as he is highly anxious and struggles socially)
Yet I sometimes have to take them shopping :( I can't measure feet if they aren't with me. Everything else I do online.
Guess I will eventually get use to other people's tutting and comments. As if I enjoy taking my kids places which they hate. 
At least DD1 and DD2 adore shopping and are a dream to get shoes for.
Hopefully that will be the last shoe trip for a while.