The last two blogs were about assembling the raw materials, this one will be about putting it all together. Synopses are always written in third person, present tense. Start with an opening paragraph that says what the novel is about and the story line. It should be clear from this what genre it falls into. Also make it clear if the structure is non-linear, for example, there are two or more parallel plots, or multiple voices. Let the reader have a good idea of what is coming.
Now write out the plot, concentrating on the most important story points and summarising the rest - 'After an unpleasant encounter at school, Jennifer decides...' The unpleasant encounter may have been worth a chapter to itself, but the important bit is the decision. Be bold, be brave, be ruthless. You can't get everything in (because then it would be the novel). It might inspire you to go to the cinema, as films often come with sharply written synopses covering the main plot points, the characters and the themes into one or two short paragraphs.
7 things to look out for...
1. Tone. The tone of the synopsis reflects the novel, so if the novel is humorous, so should the synopsis be.
2. Verbs. Use the most active verbs you can. Characters shouldn't go anywhere, they should rush, run, sidle.
3. Time. Because you're concentrating on the best bits, it's easy to make vast leaps in time that give the synopsis a stop-start impression, or completely lose...
4. Logic. Which can all too easily go out of the window as you cut, cut, cut. My first synopsis included the line 'Suddenly she realises she's having an affair.' What - she was just walking down the street when, whoops, it happened?
5. Genre shift. It starts out techno thriller, ends up as romance. Or vice versa.
6. The End. If the butler did it, say so.
7. Confusion. You need a willing volunteer for this. Get them to read it, and if they're confused at any point, you need to rewrite.
And there it is. Easy peasy.