Learning to re-arrange, simplify, change subject of very complex algebra?

Hi there

I have posted on a similar theme before. I am 32 and have a degree in Mechanical Engineering, but took a foundation route rather than English A-Levels. There was also an 8 year gap between the foundation course, and the 'GCSE' grades I took aged 16 which would have covered basic algebra.

Because of this, I think I forgot, or failed to learn, the keys to a lot of basic algebraic manipulation. Im fine with straightforward examples of re-arranging, simplifying, factoring, making so-and-so the subject - but as soon as the examples become complex, and require a number of steps and techniques, I am totally scuppered.

I have got 6 books on basic algebra from the library, and the examples they have are all very simple and I can understand them. But in many of the maths problems I am trying in an A-Level textbook, and indeed in many of the engineering problems I remember at uni, they require you to do multiple things and to see certain relationships that it seems you either have the 'knack' for, or you don't. I want that knack!

Can anyone recommend a book that would present numerous multi-step worked examples of algebraic manipulation? How do other people usually develop this capacity? It feels like solving so many of these things is more like solving a puzzle rather than applying a simple rule, or spotting which of several rules you need to apply in a given example.

Not explaining myself very well, apologies.