1. Mind first. No matter what bad things happen around you, don't let them affect your mood. Don't give yourself pressure, because only when you are in a good mood and have little pressure can you communicate with others better. Playing a good emotional card is contagious, making the person you talk to feel comfortable, and people are reluctant to talk to others when they are under pressure.
2. Secondly, your expressive ability. First of all, you need to know everything you want to sell. You should start with its function, appearance and audience. These are all ready, it depends on how you express them. It will be a bit difficult to describe them directly. Why not make a draft first, write out what you want to talk to the customer from the moment you meet the customer, and then talk to the customer according to this draft when you really meet the customer. Don't be too rigid, add some casual remarks appropriately, so there will be no topic in front of customers.
3. Your mind is always faster than the customer. If you can't do this, you will be sold back when you meet smarter customers. You should be able to control your conversation, and don't look like you are stupid and the customer runs away after talking to you for a while. You should always remember the purpose of your speech.
Let me briefly talk about these points first. I recommend you to watch Zhou Rong's video Face-to-Face Consulting Sales, which is very good.