text-align: center (not centre) is your
best bet. There are things you can do to prevent the items from breaking to
a new line, such as setting a (max-)width on images inside this div based
on media queries. But as far as aligning them in the center goes, just use
text-align and if you want to break to a new line, a simple
br will do the trick.
You said you played with margins. If you want to space elements out on
the same row, keep using the
margin property, but in
addition to the
text-align on the parent div.