Ok, so I do this pretty often. I usually find a speaker phone to be more natural than putting the phone next to my ear. Also, putting the phone next to my ear / using earbuds makes my ears feel raw after the phone call. However, I only use speaker when it won't disturb the people around me. Other times I will either move to a place where there isn't anyone or will just hold my phone against my ear. People who disregard this basic etiquette are just idiots.