The price is the part everybody reads and the smallest part of the document. What decides whether the job runs smoothly is the scope: what is included, what is not, and what you have assumed to arrive at the figure.
Write down the specification you priced. "Supply and fit six standard white sockets" and "supply and fit six brushed steel sockets" are different jobs at different money, and the difference is discovered on the day unless the paper settles it first. Name the make or the grade where it moves the price.
Say what you have assumed about the site: that there is parking, that the water can be turned off, that the loft is boarded, that somebody will be there to let you in. An assumption written down is a conversation before the job. An assumption left in your head is an argument during it.
Then say plainly what is excluded. Making good, decorating, removing debris from someone else's trade, scaffolding, permits. Exclusions feel awkward to write and they are the cheapest insurance on the page.