Assertiveness is a skill that can be taught but more often than not, it’s something that people learn to do in varying degrees through experience and practice. Not everyone is fully aware of the different techniques but it’s worth getting to know them in order to expanding your capabilities. These include: (in no order)

Repetition often referred to as the (Broken or Stuck Record) – meaning simply keep repeating your request or refusal every time you are met with resistance or when another person will not take ‘No’ for an answer. If the resistance is constant then consider applying some sanctions.
Part Agreement – It can be helpful to find some limited aspects or principle that agrees with an antagonist.
Fogging – Giving a minimum or limited response without being passive or aggressive.
Inquiry – Requesting further information avoids saying Yes or No.
Assertion – This can mean you agree with some criticism without letting up on the demands.
The “I” Statement – Enables people to voice their personal position without denying the other. persons opinion. The “I” message is less critical then using the “You” message.
Refusal – Means “No”.
Decline – Means you don’t want to cooperate or participate.
Ignore – Is the avoidance of giving a response.
Explain – When giving an answer, you can (if you wish) explain why.
Apology – Sorry, I can’t or I’m not allowed.
Demand – Insists on a course of action.
Persistence – Just keep following through with a particular course of action.
Denial – Meaning No to a request or something isn’t true.

Self-Assertiveness
Besides these techniques there are certain self-assertive traits and characteristic that are so important to assertiveness it would be difficult to do it without them. These being:
– Staying cool, calm, collected and in control.
– Being insistent, firm, determined, forthright, strong-minded, forceful.
– Take self-responsibility, be honest, clear, direct, respectful, confident.
– Listen, be persuasive, be willing to be flexible.