Three options:
1. Craft out of normal wood with normal tool -
a. look for Exceptional items with high resists in Physical, Cold and Poison, and as close to normal base resists as possible in fire and energy.
b. Imbue Fire and Energy
c. Imbue other properties as needed.
d. Enhance with wood to suit (preferably with one of the enhancement tools), probably Heartwood to try to get one of the rare properties.
2. Make out of a special wood with low resists in Fire and Energy, with a normal tool.
a.-c. Pretty much the same as 1.
Wood choices for crafting can cause issues, as many add an additional property (forcing you to only imbue 4 properties). However, that's your call, and if you actually want those properties and are willing to sacrifice one slot, they can be useful.
Examples:
Ash: Perfect wood for imbuing fire, as it adds 0 to fire resist. While it adds 20% Lower Requirements, the 6 per piece it adds to Energy means that you probably WON'T have to imbue two resists, so you would be theoretically swapping out the energy resist imbues for it, and it will allow you to keep your armor on despite curses.
Bloodwood: Adds 2 HP Regen
Heartwood: Adds random property
Frostwood: Adds more total resists, no second property, and is low in fire (only +1). Like Ash, it is high in Energy resist bonus, so you might end up with enough energy resist that you only have to imbue 2, 1 or even no pieces with Energy.
3. Make with a Heartwood Runic, hoping to get only properties you want (but especially fire and energy resists as properties, near maximum/higher than what can imbue them to due to Arms lore/EX bonuses). Imbue (mostly raise/Lower) properties around those. This is the most expensive method, and not recommended.
If you use method 1 or 2, only craft for 2 of the slots initially. How the resists end up may make you choose to craft, imbue and/or enhance the last 2 parts differently. A prime example is the darkwood armor set, where before imbuing came along, most people crafted 5 pieces out of one wood type, the last out of a different type, because that caused all the resists to max out, when using all one wood type left some resists short. The same thing holds true for Imbuing (and wood choice) for the last two pieces - you can get more properties onto the suit by only putting what's needed to cap the resists (or LMC, or other properties) from the first 4, then using the leftover space for new stuff.