I would go along with the general advice already given.

Collect things that strike you, interest you and make you happy. That is the most important thing with any collecting is that you are enjoying your hobby and that the items you gather actually are charished by you. Otherwise, some day, you might feel unhappy and feel that you just have junk. While some chips may appreciate in value, others might not. The only value left is your personal satisfaction and enjoyment.

Second, find an area that is easy for you to collect or that you have a specific interest in. Enough of an interest to go through some trouble and effort. Considering that you are in the UK, (is that what you said?) collecting from there or other European countries might be easier as you might find other local collectors you could trade and socialize or go to casinos with. That is a big part of it also. The associations and friendships that can develop when you and other people with similar interests get together. If, on the other hand, you want Las Vegas chips, than you will either need to do more traveling or buying from eBay etc. which could involve much more hastle and effort. Travel, Customs hastles with international mail. Postage....

If you have time and enjoy traveling maybe start with collecting chips from places where you visit. That is how I got started and where I largely am today. There was a time when I bought a lot of chips on to get my collection going and I do still get some of my chips as from some NIS (New Issue Service) dealers that I have bought from over the years. I started picking up chips just by playing and now have taken a little more interest in some older aged chips. Thus I am largely just picking up what I can when I go somewhere. Besides, I have had to reign in my spending a bit lately so getting chips myself can often be less expensive. And a little more fun too, I think. At first, I would pick up a chip or two from the tables when I would be playing blackjack or other games somewhere or would pick up tokens from slot machines. Some chips may be mementos of my first Craps game or my first win at Roulette... As I said before, no matter what condition the chips are in, or what happens with their value they are still important to me because of the fact that they remind me of my personal experiences at that location or playing a certain game. (souvenirs).

Lastly, there are Sooooooo many chips out there that, unless you are very wealthy, it is impossible to have them all. Therefore you should probably find a way to define what you want to collect. As others mentioned, by subject, say Dogs, Hot Rod Cars, Baseball, NASCAR Racing, Rodeo, Music, Pop Culture, Special Events and Holidays... There are so many subjects for LE (Limited Edition) chips that are released. Or by Location, Era... Some people like to collect the chips that were used in speakeasies and illegal backroom casinos of the past. Others collect chips from historical Las Vegas Casinos that are long gone etc. There are some that collect the personal home poker sets that people used to use throughout history. I don't limit myself to such specific catagories but I do limit myself by the artwork, design or other cheracteristics and if I like it and it interests me personally and or generates a deep personal like or memory etc. Like the paintings on the wall the art, history, memories or stories in the chips often hit me personally. I do also collect specific chips that strike a part of my childhood or other part of my life in a nostalgic sense. Certain music groups from Hard Rock that are part of my High School or College days that strike memories of that time of my life, for example.