1. If you must, you may wear flats to a formal event.

While dress codes dictate that you must wear heels to an event, there’s nothing more unsightly than a woman wearing shoes she can’t walk in and it would be painful to watch her fumbling all over the venue. If you are more comfortable wearing flats then, by all means, go ahead. Choose your flats with care and ensure they are clean and chic. Here is an example of wearing flats with formal wear.
2. When you have guests

If guests come to your home for the first time, show them where the bathroom is so they can freshen up, and only then invite them to join the others.
If your guests brought food or drinks as a gift, put them on the table where everyone can try them.
3. When you are a guest
If you need to leave a party early, just ask the hosts for a moment and tell them that you have to go. Don’t say goodbye to the other guests as they might take it as a cue to leave.
4. In a restaurant
If it’s very hot, don’t cool yourself down by waving a napkin. Just tell a waiter that you are not getting enough fresh air, and ask him to turn the air conditioner on.
Don’t lay out the contents of your purse in a public place.
If you need to brush your hair, do it in the ladies’ room.
You can put on lipstick at the table. However, you should only apply mascara and powder in the bathroom.
5. Your mood should never affect your manners
Even if you’re having the worst day ever, you should always keep in mind that the people you’re interacting with might not know this, so you should never take it out on them. If anything, put a smile on your face and try to conduct the rest of your day with positivity–this might even elevate your mood. The same goes for people you encounter who are rude and snappy toward you. You don’t know what they’re dealing with, so just smile and be polite. Maybe your positive vibes will rub off on them!
6. Table manners

It’s rude to refill only your glass. First, ask if the person sitting next to you would like a refill.
Don’t take a long time to choose the best piece of food on a plate. Take the nearest piece.
Don’t put a soup spoon on the table during dinner or after it. Leave the spoon in the bowl so as not to make the tablecloth dirty.
When holding a teacup, place your fingers to the front and the back of the handle.
However, you can loop your fingers around the handle when drinking coffee.
7. Know when and where to take your hat off.
If it’s a fashion hat you’re sporting, such as the hats Princesses Eugenie and Beatrice of York are commonly spotted wearing, then these are acceptable when indoors, at weddings, during formal events, garden parties, and at religious services. Be courteous enough to take your hat off when you’re obstructing the view, such as at a wedding ceremony or at a theater, according to Emily Post. Of course, it’s unacceptable to wear casual caps (such as baseball caps) while indoors, during meal times, and when being introduced.
8. Car etiquette
When a lady gets into a car, she shouldn’t “step“ into it. She should sit on the edge of the seat and ”pull” her legs into the car. When getting out of the car, she should put her feet on the road and then stand up.
9. Stash the smartphone
This rule should go without saying, but we all forget. It’s the absolute worst to be with people who are always on their phones. Emails, social media and conference calls consume my life, but I try really hard to put my phone down when I’m out with my friends. I make the extra effort when I’m with my parents or any people over 40 because I’ve personally found that older generations find it much more disrespectful to have a phone out than our generation does; in cases like that I keep my phone completely out of sight.
10. You may leave a maximum of two buttons undone on your shirt.
Anything more would look too relaxed and almost sloppy. Leaving the collar buttons might come off as too uptight. One is acceptable, and two buttons undone are enough to look laidback and approachable.