Keep the mallet away from the stock, especially if you are just starting out. I use the Pfeil # 12 1mm V gouge most of the time. Draw your lines, and then barely scratch in the first cut. If there are areas of the curve that are a little flat, or a corner that'a a little squared off, when you go back over it to deepest the cuts you can then make the necessary adjustments. This is particularly true with incise carving. With raised carving you can knock off more wood to get things to round up nicely. I often use the Pfeil # 11 1mm U-shaped gouge for cutting in the concave portion of volutes, but some times the # 5 #as well as some others) on larger or more gently shaped portions.
In addition to the Pfeil tools, I have a set of micro chisels I got from Woodcraft labeled Dockside Micro tools, that are marketed largely to modelers. Remember, in general your tools can't be too small or fine, but they can be too large or coarse.
Scrapers (like the David Fisher ones from Brownells) and pen-sized sanding sticks can be very useful in shaping the tops on raised carving.
And learn how to sharpen the stuff. A leather strop is mighty handy to refresh an edge when you feel like the chisel is starting to grab rather than cut.