So I've been min-maxing my starting builds recently, and this got me thinking about which skills are more or less difficult to train. So I tried to draw up a list of skills categorized by training difficulties. It's also relevant when considering which dwarves are expendable of course.
Any input on this is appreciated.
Not included in ranking:
Butchery, Tanning, Gem Cutting, Wood Cutting, Dyeing, Soap Making, Wood Burning, Potash/Lye Making, Milling, Threshing, Herbalist, Cheese Making, Milking, Pressing, Bee Keeping, Weaving, Strand Extraction, Pump Operating - IMO these skills are not worth being trained explicitly. If they are used frequently enough for the training to make a difference, it's usually frequent enough so the dwarves train easily by just doing the job.
Dyeing, Hunting, Trapping, Animal Dissection, Training, Caretaking, Glazing, Wax Working - I don't know a lot about those skills and how they train.
Consoler, Pacifier - I don't really know how it trains.
Very Easy:
Melee Weapon Skills - train by barracks
Mining - obviously
Stone Detailing - smooth large amounts of stone surface
Book Keeping - trains itself by Highest Precision setting
Flatterer, Conversationalist, Comedian, Intimidator, Persuader, Negotiator, Judge of Intent - train by inactivity
Easy:
Gem Cutter - Since you can cut regular stone now.
Mechanic - create mechanisms / stone is everywhere
Stonecrafter - create stone crafts / stone is everywhere
Mason, Cooking, Brewing, Farming (Fields) - train themselves by frequent use
Fishing, Fish Dissection - if you have good fishing grounds of course
Siege Operator - build a catapult in an area with lots of stones and fire at wall
Appraiser - may be more difficult if not all civilizations are trading
Medium
Bone Carver - easy if you have a bountiful animal industry
Leather Working - see above
Gem Setting - since you can set regular stone now.
Glassmaking - sand is an infinite resource / easy if you have magma
Carpenter - used a lot, but requires wood cutting which is in an unsafe area
Hard
Weaponsmith - create bolts, they can be melted with good yield / Medium if you have magma
Metalcrafter - easier with magma and lots of gold
Armor Using skills - Very Easy with a danger room
Crossbow Making - Medium if you have a good bone industry
Very Hard
Armor Smith, Blacksmith - need lots of bars and fuel, bad yield when melting
Siege Engineer - product needs lots of wood
Doctor skills - Medium with a danger room I reckon