"Did I make myself clear?" is often said when a parent is scolding a child. For example, "Do your homework! Did I make myself clear?" If you say this very politely to a stranger, I don't think they would be offended. It is kind of a strong statement and it can be worded differently to make it more polite. Avoid saying, "Did I make myself understood?" It's a little awkard. Saying, "Any questions about what I just said?" comes across as polite and can be used instead. Or, simply just, "You see? Any questions about that?" You won't have to worry about it being taken the wrong way if you say these.

When I explain something in English, for example, about sights of my town, I sometimes use these expressions " Did I make myself understood? or " Did I make myself clear?" This is when I'm not sure if they understand me or not. I sometimes do volunteer work as a guide. Recently I've read that these expressions are not polite. Is that true? And if so, what sentence is appropriate in this situation? Thank you for your help. If you want to ask your tour group if they understood you, you may consider asking questions that require an answer other than "yes/no" For example: What other __________(has/have) this/these/those same __________? This will allow your group time to think about the subject and respond back. Then you won't have to ask if they understood you. You will know by the answers or questions they give or ask. I hope this works for you.

You can also elicit feedback by asking "How was my explanation?"

do you know what I mean? do you know what I'm asking? you know what I'm saying?