Ian,
I don't know your level of experience with styles, so forgive me if I
tell you something you already know.
I use the "Default Style" simply as a starting point for all my other
styles. I rarely actually apply the "Default Style" to a given paragraph.
LO's styles are hierarchical in nature, so that subordinate styles will
share certain formatting characteristics of the parent style.
Rather than use LO's built-in styles, I tend to create my own, so my
style hierarchy looks something like this:
Default Style
BodySingle (just like Default, but with a 1 pica empty space above
the paragraph)
BodySingleIndent (just like BodySingle, but with no empty space
above the paragraph, and the first line indented 2 picas)
BodyDouble (just like BodySingle, but with double spacing, and
an indented first line)
Title (Usually a different font style and size and centered with
spacing above and below the paragraph)
Each subordinate style will inherit most formatting characteristics from
the parent style, but then change one or two particular attributes. For
example, BodyDouble will inherit its font (style and size) and margins
from BodySingle, which, in turn, inherits those attributes from Default
Style. If I change the font style or size in Default Style, then that
change will apply to BodySingle, BodySingleIndent, and BodyDouble. It
will not, however, affect my Title style as I control the font at that
level.
Likewise, BodyDouble has a unique formatting attribute. It is double
spaced. So, if I change the line spacing in Default Style (say from
single to 1.5 lines or to a proportional line spacing) that change
*will* carry forward to BodySingle and BodySingleIndent (both of which
share the line spacing of Default Style), but it will *not* affect the
line spacing of BodyDouble, which will remain double spaced, because I
set the line spacing for that style within BodyDouble itself.
The key is to know which attributes are dictated by any given paragraph
style and to make changes at the proper style within the hierarchy that
it affects all of the paragraphs you want changed, and only those
paragraphs.
When making formatting changes to styles make sure you do it properly.
Do not just put your cursor in a given paragraph and start changing
formatting from the toolbar or the "properties" panel in the sidebar.
That will result in "direct formatting," which will not change the
style. Instead, make sure you right-click on the particular style you
want to change in the style list (sidebar), and select "Modify." Any
changes you make should affect that style and any subordinate styles
that share the same attribute that is being changed.
If it doesn't, then that most likely means you have direct formatting
peppered in along with style-based formatting. If that is the case, then
I would follow Steve's advice and select all of the text (Ctrl-A) and
clear direct formatting (Ctrl-M). At that point, you should have all of
your formatting controlled at the style level.
I hope all this makes sense. It's easier to do than to explain.
Virgil