It's similar like the eternal question of who was first, the egg or the chicken :-)
Dry wood results in almost.. no risk in cracking, but harder to carve.
Fresh wood results in easier carving but also pretty good risk of cracks.
If you use dried wood, choose something relatively soft, like birch indeed. Cherry or apple wood give also nice lines in the wood sometimes.
But a dried burl is rock hard, not possible to do it without powertools.
A way to prevent fresh wood cracking is to store the project over night (if you didn't finish it in a day) in a paper bag with all the wood shavings added, and slightly opened, so no fungus will appear.
When you're finished do this for about 2 weeks, and then a good chance on it being ok :-)
Also boiling in salt water should also reduce the cracking a lot when finished carving... but again, dry it for a week or 2 after that, with the wood shavings from the project.
With this i have personal expierence. I did it with the kuksa below from a fresh burl. I also added 2 tea bags of black tea to darkening the wood a bit.
Another way of preventing cracking is to boil it in milk when done. apparently the milk contains something that does something with the wood blabla.
I have not tried this myself, but a good friend of mine who is very much into the old school ways of woodworking and preserving, uses that technique, and it seems to work.
I would suggest to start with a simple piece of wood, nothing fancy, since it takes some practice to make it good, using different kind of carving styles etc.
And as last, what you wrote yourself is 100% correct. It needs to be functional. Looks can come after that, but functional is more important.
You see sometimes these great artworks of spoons and kuksa's, but I'm not into that. Not enough skills nor patience for it :-)
Some of my humble creations so far are below pictured.
Missing is 2 spoons that broke in the mean time, 1 beautiful spoon i finished recently but my kid played with it and now it is lost, and a burl kuksa (my first one) which cracked.
My favorite spoons are the 2 with the spatula endings, which are perfect to clean a pot or pan after cooking.
