>onyx do you use a tablet?
Unfortunately I don't have one. I'm doing everything through low level node manipulation. First I use the (b)ezier tool to define the shape roughly with straight lines and then I use the (n)ode tool and drag nodes/paths around and change the node type if I have to (shift+s=smooth [square], shift+y=symmetric [square] and shift+c=corner [diamond]).
With a tablet my workflow won't change much. However, it would be more comfy and I could sketch better around with the (p)en. Those sketched lines are only used as some kind of guide/reference and I delete em afterwards. The reason for that is that the node count would be too high and manipulating/tweaking paths takes way longer if there are more nodes than necessary. Therefore it's important to keep the node count low.
Inkscape comes with rather good documentation (help->tutorials). Work through it and you'll know the basics and a few handy tricks. Try to learn the shortcuts of the tools you're using often and you'll be able to improve your workflow. Other workflow improvements will pop up on their own with more experience.
There are also lots of tutorials on the net. I suggest to start out with interface stuff such as buttons and shiny text before starting with your own complex paths. The learning curve will be less steep then. And even if you give up later on, your time commitment won't be in vain, since those basic skills are already useful on their own. Eg you could use it then at least for website layout mockups, interface elements and diagrams.