I have a 12v polisher form Halfords and....
 

...I want to get sparkle out of my Royal Blue Tourer.

I'm on a budget so:
What should get to cut it back?
And what should I do then?

PS: Couple of years ago I used Tesco Daisy and Tcut (by hand) followed by Turtle wax on my White Gold Tourer. It made a massive difference but it took all weekend.

Well they aren't great shakes (either of them) at really going to town in a professional style: but they will help speed things up and make it a little easier. Be ready for taking the weight and holding either against the car sides especially below the (car's) waist line.

A simple suggestion would be to follow a single manufacturer system like this one Meguiars deep crystal 3 step system. I've used the Meguiars on my Starlight silver and it does pretty well.

https://www.amazon.co.uk/Meguiars-De.../dp/B002W6C6NE

(N.B this is not a recommendation for Amazon)

Cheers for that. Would you still recommend washing in Tesco Daisy first??

Off to the shops in a few days to buy the Maguires stuff. Would a clay bar be a useful addition? and would it be best to use it after step 1?

Cheers

In short -
Wash
Clay
Wash
Step1
Step2
Step3

You forgot prewash, also de-tar before claying as tar will destroy the clay in minutes ;)