What I did last year to study my essays was break down every essay into 8 points per paragraph, then 2 or 3 for the intro and 2 or 3 for the conclusion.
I thought I'd paste an example, so here's one for a 20 mark FPTP essay.
Intro
Used in British General Elections
Winner takes all
More negative because of proportionality and wasted votes
Voter Choice
Easy to use and understand
Clearly identify why representatives have been elected
Simplicity leads to higher voter turnout
Scottish turnout in BGEs higher (71% to 50%)
Wasted votes
Only 1 MP voted per constituency
In 2015 19mil cast ineffective vote (70%)
Encourages people not to vote
Stable Government
Usually provides a decisive result
Few exceptions like in 2010
Strong single party majority – no need to rely on other parties
2015 conservatives had a majority were able to pass legislation
Can result in coalition governments and hung parliament
No one votes for a coalition – creates unhappy publoc
In 2010 Tories had to negotiate with Lib Dems to create a coalition
Made the government look weak and indeciside
Constituency Link VS Proportionality
Strong link between voters and representative
Makes MP more accountable
If MP familiar, more likely to visit
Philippa Whitford high profile SNP candidate for Central Ayrshire
Delivers unfair result
Proportionality between seats and votes poor
Concentration of votes results in more seats
In 2015 UKIP won 12/6% of votes, third highest but only 1 MP
Conclusion
Negatives more impactful
Majority can be formed with minimal support
2010 Tory majority off 12 MPs, only won 36.9% of votes
I hope this makes sense. This essay was in my prelim and I think I got 19 or 20.