It's all too easy to get caught up in thinking that expensive soaps or creams will guarantee good lather, but the truth is it comes down to practice.
Using lower priced products is where i would suggest you begin.
@donnie_arko recommended Palmolive shave cream. It's good stuff at a low price.
Nivea shave cream (also in a tube) is also good (available in Home Bargains, et al)
At their price point, you could practice lather to your hearts content and it would only cost you 50p at most.
You'll get there soon, and it will come naturally.
One thing to note - is a 3 pass shave necessary? (Lots of youtube shaving videos feature 3 pass shaves when two passes will suffice)
If your lather isn't too great, you'll certainly cause more irritation. This is what makes lots of people who try traditional wet shaving give up. They blame their tools and not their technique and ability.