I like inscape a lot, but sometimes, when you want to do some quality work, it takes a lot of time to design and create stuff. (I do not say that inkscape is slower than other software).

So I was thinking if there could be ways to optimize productivity to reduce the amount of time it takes to create stuff in inkscape. Here are a few suggestion of mine.

1-Bigger screen: That might seem stupid, but with a bigger screen, there might be less scrolling and zooming to do in the creation process.

2-Predesigned functions/Macros: If there is some process that are done across many work, making a function so that the effect can be reproduced in one click could be a good think. (Ex: Many times, I make drop shadow on text to increase visibility. I could create a custom drop shadow function that moves the object by the offset I want.)

3-Templates: There could be common layout that I reuse in many works. For example, when I draw cards, the sheet layout it always the same. So I could pre-draw my card borders and cutting line in a template file that I simply load when I want to create cards.

Does anybody have other suggestions on how to work faster in Inkscape?

1. I don't understand your bigger screen request! The only way to get a bigger screen is to get a bigger monitor, or am I missing something? Inkscape's window can only be as big as your monitor. You can hide a lot of the control bars although some are pretty necessary. You can zoom inkscape to any level. You can even zoom and save as default so Inkscape opens at that zoom every time.
2. Predesigned macros - these would be extensions and filter effects. The filters are easy to customise and save. Custom extensions will require considerable programming skills but if you really want to the option is already there. For instance your drop shadow is in the filters menu under shadows and glows. you can customise it in the filter editor and save it as your own.
3. You can set up your document the way you want it to look and save the document in your user folder in the templates folder (In windows xp, C>documents and settings>yourname>application data>Inkscape>Templates). Thereafter it will be available in the file > new menu.

Learn all the keboard commands, and use them?

I don't understand your bigger screen request! The only way to get a bigger screen is to get a bigger monitor

Yes, Big Screen = Bigger monitor.

I did not know you could save customized filters. Could be useful.

Learn all the keboard commands, and use them?

I am currently using a lot of them.