Originally Posted by stut

Doing England on the cheap is possible. Look at pre-booking hotels like Travelodge (different to US Travelodge) and Premier Inn. If you want to eat out, lunchtime offers are much better than evening. Lots of supermarkets have good food options, and vouchers for eating out are everywhere. Transport can be expensive, but there are bargains on trains and domestic flights if you're flexible and book early (for a fixed service). But if you want cheap, you're much less likely to find it in London than elsewhere in the country.

Services through the tunnel are run by Eurostar. These are priced like air fares, so again, book early.

Once in France or Belgium, then you have the option of using a Eurail pass (note that this term refers to the pass, not the train company - most European countries have several train companies these days!) or booking services independently. If you're flexible and can commit in advance to specific trains, you may find the latter better value.

As for where to go? Well, what do you like to do? Do you want to visit city, seaside, countryside, mountains? Do you want fast trains, overnight trains, scenic trains, comfortable trains? Are you there for the food, the sights, partying, museums, relaxing? And crucially, how long do you have?