Even if Labour need to get their house in order, I still don't understand why someone would stick a X next to a Tory candidate instead. That's just me though..
Fear and simple solutions.
You create fear, a much greater motivator than opportunity. If I invite you to walk towards me because I have something you might like, you might do, but you might not, and even if you do, it is probably cautious walking. If I tell you there is a fire behind you and it is heading your way, you'll run towards me if I tell you I have a hose.
It is very hard to fight politics when you take it down to that level. You either have to do something to take the fear away, make it seem less obviously bad, or offer your own simple solutions (probably knowing that won't be enough anyway).
Take the Labour Party in 1997 - as much as people may hate them for what they were, they got into power by offering some basic solutions to complex situations that had generated a lot of fear.
Their manifesto included things like:
Protect the NHS and spend 100m on patients by reducing spending on Admin and cut waiting lists
Free Childcare for 4 and 5 year olds
Cut class sizes to less than zero by increasing spend on Education as a % of total spend
Minimum Wage, Maximum hours and guaranteed time off
Locking up youth offenders more often and more quickly
Devolution for Scotland, NI, Wales, London & the Regions (the latter didn't really work)
They were not completely left wing, in fact, the Tories probably wouldn't disband any of these items or suggest they would.
They responded to potential fears, real or otherwise - if I get ill it may take ages to get seen, I can't get a job because childcare costs too much, I won't earn enough money because employers hold all the cards, I'm worried about all that nasty crime the right wing press tells me exists on my doorstep, the UK Govt doesn't care about us Scots etc.
A party needs to address similar fears of today:
My job is at risk - it may be pinched by a nasty immigrant or go to their country
I don't have a job - as much as benefits helps, I actually want a job (or think I do)
The school I send my kids to is probably teaching them crazy stuff and isn't much kop beyond that
The Tories have clear ways of handling these problems, you may not agree with them personally, but to plenty of people they offer a solution. Like the Trump policy of building a wall to keep the immigrants out (which completely ignored the fact most of us come via air), Brexit and control of borders is the easy solution. Stops all those pesky foreign people who speak other languages from coming. A Party needs to do two things - first, show up the holes in the wall. Second, offer something else that sounds just as simple and effective.
Jobs offshore - USA went after Trade policy - we'll charge the nasty Chinese more to send their shit over here so everyone will build and buy USA. The trade deficit actually widened, but it still sounded good. In the UK, you have the Brexit problem to solve - how to sell stuff abroad, so you tout free trade deals and show the EU as a blocker. Our Sovereignty will set us free. Time for other parties to accept the world as it is - offer trade policies for a world post Brexit and stop moaning about it. There is a fucking huge trade bloc just to the right of the UK, start offering policies to fix the Brexit red tape problems.
And so on.
You get Power first, then you fix the shit that matters but people don't vote on.