Back in the early eighties we had a book in the sixth form that listed all the universities, (not so many back then) each course and what their usual offer was. Can't remember if it was an official UCCA book? We also had copies of prospectuses (prospecti? 
) for most of them and another book with polytechnics and colleges of higher education. They're pretty much all universities now.
We then sent off for our own prospectus. There weren't any open days that I can remember. We just applied for 5 through UCCA and got called up to visit for an interview. Some unis were good at showing you accommodation during the tours, others less so. You then received an offer (or not) within a few weeks and chose your firm and insurance. That much was the same. The order in which you placed them on the handwritten form could be significant. If you put a posh uni fifth, they might take the hump! Nowadays the order isn't important or shared with the unis as they don't just receive a photocopy of your form.
One thing for certain, not a single parent went along! I couldn't believe how that's changed. DS1 went to about 8 open days, and seeing a sixth former without a parent was rare! I guess times have changed. My degree was almost free. No fees and I got about £800 of a grant which paid for 1/3 of my accommodation and living expenses, my parents topped it up to £2000 per year. You felt grateful to get a place. Now it's much more like a business transaction as so much money is involved. Universities are out to sell themselves to ensure their courses are full. And parents and students want to get their money's worth!
I went with DS1 to 4 universities, his father took him to one but left him there and he went to one independently. He also went on sixth form run visits to Oxford and Cambridge, which was just a coach drop off and pick up on an open day. He obviously gained in confidence as he saw more. I trailed around with him on the first couple, then left him to it and sat in a café for the rest, except to look at the accommodation.
DS1 is NT, though. I would definitely recommend accompanying anyone who isn't NT. You certainly won't look out of place.
DS chose his top 5 unis and applied via UCAS and offers started trickling in. He got 5 offers with no interviews, though he didn't apply to Oxbridge. He was invited on offer holders days, which are basically another not-quite-open day by subject. He was certain of his top choice but revisited another two in Feb and March to make up his mind between them for his insurance.
So, altogether he visited universities 10 times! Busy and expensive!