You should read the Opera7SkinningGuide to understand a little about how Opera customises the user interface first. Every aspect of the UI can be customised in Opera, and luckily skin authors do most of the hard work. However, sometimes there are bits of the UI that are not to a personal preference, and this is where tweaking a skin comes in handy. See EditingINIFiles for info on how to edit skin.ini.
The addressbar has a margin at the top and buttom, to save a few pixels adjust
[Addressbar Skin] Padding Bottom = -3 Padding Top = -2
If you want to trim it even more, lower the numbers more. This works best for me however.
To get most space from the page bar, find this in skin.ini:
[Tab Button Skin] Type = BoxTile ... Margin Right = -11 Padding Left = 4 Padding Top = 2 Padding Right = 9 Padding Bottom = 1
You'll want to play with the padding and margin values - the values above are taken from my BreezeSkin which has very compact page bar tabs so try these values. If your page bar is at the bottom then you edit [Pagebar Button Skin.bottom] in the skin.ini file as well.
To further optimise the page bar, if you remove the icon on each page tab, you can save quite a lot of space overall. Add this 1x1 pixel .PNG image (right click here to download it) to the small_buttons directory in the skin. Then change the following skin.ini lines (maybe the original images (bit after =) have a different name (due to different skin authors) but the bit before the = is what you should search for):
Window Document Icon = small_buttons/windowbar_doc_complete.png Window Document Unread Icon = small_buttons/windowbar_doc_complete_unread.png to Window Document Icon = small_buttons/bit.png Window Document Unread Icon = small_buttons/bit.png
Bookmark Unvisited = icons/bookmark_unvisited.png Bookmark Visited = icons/bookmark_visited.png to Bookmark Unvisited = small_buttons/bit.png Bookmark Visited = small_buttons/bit.png
If you want to go even further, and save some space in the bookmark manager (CTRL+ALT+B) and hotlist bookmarks panel (F4 and CTRL+1), then you can change the folder icon and open/close arrows (were saving dem pixels here!). I've made some micro arrow / folder icons which you can download here, and simply place them in the icons directory in your skin. If your skin does not use the same names, then make sure you change your skin.ini lines to read the following:
Folder = icons/folder_closed.png Folder.open = icons/folder_open.png Thread = icons/thread_closed.png Thread.open = icons/thread_open.png
Lots of skins waste far too much space on the panel buttons in the hotlist (maybe more aesthetic, but considering the important function of the hotlist, it is wasteful). If you want to gain more space to actually see information in the hotlist, edit:
[Selector Button Skin] Type = BoxTile Padding Top = 4 Padding Bottom = 4 Padding Left = 4 Padding Right = 4 Margin Top = -3 Margin Bottom = -3 Margin Left = -2 Margin Right = -2
Again, play with Padding and Margins until you get optimal use of space. To get a more 'tab-like' appearance and reduce wasted space even more, try deleting the following from the [Selector Button Skin] and [Selector Button Skin.selected]:
Tile Bottom = selector_button/bottomright.png Corner Bottomright = selector_button/bottomright.png Corner Bottomleft = selector_button/bottomleft.png
A lot of skins make disabled text a very dark shade of grey, which is indistinguishable from normal black text (at least on my monitor). It's especially annoying when I have to mouse over each item in the Navigation bar to work out which ones actually click. To fix this, just add the following line to any section named with the suffix ".disabled":
Text Color = Window Disabled