There is a great deal of trouble in a referendum.
The recent UK referendum on AV has shown this only too well. The overwhelming defeat of the pro-AV campaign, who actually had a very good case on the basis of improved democracy, has put back the cause for, IMHO, at least 3 years and one general election; possible significantly more. This is because the result must be accepted by any who believe in democracy, as applying at the time and in the conditions of the previous referendum. The pro-AV campaign was, in fact, politically out-manoeuvred before the campaigns had even started: not least on the timing.
There is a second thing against referendums. Many questions are too difficult and detailed to be understood by the electorate. This is not because each elector lacks the intellectual ability to understand the issues (most do, I suspect, though it may well be uphill work with some issues and quite a few people). It is for three other reasons: (i) most do not currently view the job as requiring the amount of thought that it actually requires; (ii) they are not particularly likely to ever properly hear the issues in balance against each other; (iii) they do not have time to properly find out and consider the issues.
This latter point, for a whole electorate, is actually a killing practical issue. This is why we continue with representative democracy rather than with direct democracy, even though the constraints of communication and transportation for the latter have been overcome by modern technology.
Finally on examples, and this is especially pertinent to a UK vote on membership of the EU, sensible consideration must include what is to replace the status quo. We currently have full EU membership (currently excluding Euro membership). This could be replaced by nothing, by EFTA or EEA or other free-trade block terms (and the details differ and do matter) or it could be some more intermediate position between full membership and no membership. I also think any referendum should include full EU and full Euro membership: go smoke that. [Not that I would vote for it. But the question should be put, to that full extent.]
Thus, on the EU, a simple IN/OUT question is not actually the one, though the issue might be more suitable for a referendum than many others. In fact for me, if a simple EU IN/OUT vote were put, I would be strongly tempted to abstain, either by not turning out (less likely) or spoiling my ballot paper by writing 'none of these' or 'the wrong question has been put'.
If you want more democracy, try: more frequent elections, a 100% elected House of Lords (but how?), a directly elected Head of Government (called for example Executive Prime Minister, and keeping our constitutional monarchy WRT Head of State), and more localism with better designed local democratic representation. Finally, and when we think it timely, have another go at introducing AV and/or STV.
If people want referendums on many things, but not more frequent elections, they need to consider carefully what they are thinking.