Be patient! Your child is learning through trial and error. Give them time and space! They will master the rules and guidelines at their own pace. Don't constantly watch over their shoulders and intervene. Let them be, and let them follow the rules on their own!
Use time wisely: children understand much better that way. Nobody likes being interrupted in the middle of an activity. Give clear indications of time to help them better manage every step. For example, tell them that in 5 minutes, or when the timer rings, the game will be over, and it will be time for them to put on their pyjamas and brush their teeth before going to bed. It will make it easier for them to end the game and be ready for the next step.
Make sure your child is giving you their full attention when you're giving instructions. Stop what you’re doing, go near them and make your request clear. Shouting across the house will be inefficient and will feed your anger.
Keep in mind that discipline is a love story. Every parent tries to discipline their children out of love and in order to help them grow on strong foundations! It doesn't need to be full of anger and frustration, discipline is a good thing to help guide your children and prepare them for everything life has to offer!