Firstly I don't claim to be a complete expert but I think it's more sophisticated than that. Penetrating a person's private data, just like protecting it, is a trade-off between the level of hassle and potential reward or consequent distress.
Snowden is both a leading expert and a classic example of this inasmuch he had the highest security knowledge and was accurately able to predict how long it would take the CIA to locate him in spite of his top level precautions. In other words, if they really want to know, they will. At a basic level they can triangulate usage patterns for instance, find holes via JavaScript and Flash, and in some cases determine screen size and model number of device being used. If you block all of those, you severely limit the usefulness of your browser.
As with punting, you can't make it foolproof but you can make it harder for someone to fuck you about. The extent to which you go can rationally be decided by balancing the level of security against who might want to know and the consequences if they find out. Protecting yourself against a wife or work is fairly basic but not necessarily the same. Protecting yourself against potential harassment by police who think prossies are an easy target (or punters if local laws or local prejudice comes into play) is slightly different. If you looked at your browsing history as an outsider, what would it say about you? How does that change depending who is looking and why? What would be the repercussions? Given that, what is the appropriate type and level of security?
For many, getting a separate old-fashioned phone, switching it off completely or removing the battery when not using it, and using a separate inaccessible system to browse Adultwork are all you need. Personally I'm a great fan of pencil & paper, but that's just me. As with condoms(!) getting to know how they are used properly and appropriately and choosing the right type can be more important than 'the best brand'.
When it comes to botting (e.g. Video games) I think the expert opinion is get a VPN that is a cheap one (it's less likely to be blocked by name than one of the big ones).