Harris Large Black Paint guard

The thing is nowhere near straight, waste of time and money, how they can't mould a straight piece of plastic is beyond me

Don’t bother, these aren’t straight, paint will seep underneath as it’s poorly moulded, also isn’t straight

Ok so having read reviews prior to buying this I wasnt hoping for miracles. This does do the job but it does take practice. I have made up a few do's and dont's to hopefully help.
Do's...
Do use a small brush
Do only use the middle part of this straight tool if you bought the large (I bought the large thinking I'd be able to cover bigger areas quicker! I was wrong. It's not worth going to the ends with the big one as it's hard to hold it still and bends!)
As per my comment above DO buy the smaller one!
Do (and this is the most important) do clean the tool EVERY time you move it. I simply wiped it on my painting clothes.
And now for the Dont's...
Don't over load your brush just a dab will do.
Dont push the brush to the edge of the tool, instead push the brush to the wall a little bit away and allow the bristles to fan to the edge. Pushing the brush to the tool will cause paint to seep under!
Dont try to do too bigger brush strokes just do about a 6inch stroke at a time.
Dont give up. Try an area to practice first.
But honestly if you follow my tips you should be able to get good results. It really isnt as bad as some of the reviews once you get the hang of it. And it is way quicker than masking a room!

I thought this might be the solution to cutting in but the tool is poorly cut. As it isn't perfectly straight it doesn't hug the skirting board close enough to stop paint seeping through. Don't bother, just use frog tape instead!

I bought this to get a nice clean finish especially with the wall / ceiling