How do i make a 1 amp boost converter that converts between 3-5v to 5v? Answered

Hey, so  have been buying pre built boost converters but i wanted to build my own, my question is, how can i make a step up boost coverer circuit that takes between 3 and 5 volts and converts it to 5 volts at 1 amp. In you answer could you explain what each part does? Thank you!!!