The numbers can sometimes help - imagine each volume as a book of records, and each page in the volume has a set number of records included (I think normally 4 or

. If you are looking for deaths that are quite close together (two children both died in the same epidemic), you would expect to find them on the same page or within a few pages.
If you have a fairly unusual surname and you see three people with the same surname on the death index with the same quarter/district/volume/page number, you might guess that something interesting was going on there!
Similarly, twins can be picked out by the fact that they normally have the same volume/page numbers.
Sadly, none of this helps you if you're looking for John Smith who died somewhere between the 1851 and 1861 censuses...
