In the Original Post.
• I added a section called Styles and Realms [[≈ 4e Sources]].
• I statted the wood elf.
Check these out.
The purpose of the design of the wood elf is to compare with the design of the human.
Because all races use ability prerequisites, rather than ability boosts, abilities are no longer an issue when balancing races with each other. Every race, human or otherwise, arranges the same ‘heroic array’: +3, +2, +1, +0. The only difference is, it is impossible for a player to assign the +0 to the Dexterity of a wood elf character.
With abilities no longer a balance worry, the design space that remains for other race features is beefy. Every race design has a chassis that is equal to three halffeats.
A feat is exactly equal to an ability bonus improvement by +1. A feat is worth two halffeats. A halffeat is worth roughly four skill proficiencies. Or sometimes a halffeat seems worth about two extra-good proficiencies, such as a martial weapon or a spell cantrip. A halffeat also seams worth a spell from the second spell level, such as Darkvision or Misty Step per rest, or equivalently telepathy. Tho note, Darkvision seems more comparable to a cantrip, thus half a halffeat.
During the zero levels of the Advancement table, the Race level is worth one halffeat. Then the Feat level is commandeered for the race powers. Humans choose an actual feat. The wood elf gets assigned two halffeats: Elven Accuracy and Fleet of Foot. The accuracy is a nod to the 4e wood elf, and it balances with the 5e Elven Accuracy (half)feat. I am happy how this works out, both beefy like 4e and low level like 5e.
In 5e, the intention of the elf Trance rules is to use vague language that under scrutiny is mechanically useless. By contrast, the effort to speak clearly about mechanics of Trance results in a potent elf feature. The Trance is a short rest (namely one hour). The elf is fully aware of the surroundings, and can keep guard while others sleep. An elf is immune to the Unconscious condition, thus the Sleep spell that inflicts it fails to work. By implication, an elf is always conscious unless destroyed.
All of the races equal each other in abilities and power. The human race tends to have more free choice. So character optimizers might prefer the human. I am fine with this. I prefer a more human centric setting. The versatility expresses the flavor of human learning and individuation.
In sum, the zero levels for race and feat allow a design space of three halffeats. This amount is substantial to cover an assemblage of significant abilities and powers that can prevent the different races from feeling ‘samey’.
In addition to the race and feat levels, the skill level and class levels can often even more design space to elaborate a race design concept.
The skill level supplies the ‘livelihood’ [[profession, background]]. Each race will have its own cultures and each culture its own unique livelihoods. I have in mind the ‘Grugach culture’ of the wood elf. Thus players can choose among livelihoods such as: ‘Grugach trapper’ who makes pit and snares to capture animals. ‘Cooshee trainer’ who raises and trains the Grugach elf dogs. And so on. There can be ‘Griffon riders’ and ‘unicorn knights’ in the ‘Gray culture’ of high elves. Drow females versus Drow males.
Each culture needs its own institutions that exist outside of combat. Use the skill levels of the Advancement table to spell out the stats for these.
When it comes to race specializations in combat, there can even be ‘race as class’. The zero levels include the talent level and the class level. For example, the Fighter class will use these two levels for basic Fighter abilities, such as martial weapon proficiencies. A race class can instead use these two levels for other features that are more pertinent to the race, such as high elf Elven Archer, so as to pick up bow proficiency and a cantrip or so instead of heavy armor proficiency. After this, the Elven Archer can go from there to the remaining Fighter levels or the remaining Wizard levels. Think of a race class as a kind of prestige class that can be a tweak at levels here and there, or a full class, depending on what the concept requires.
So race design includes a race level with a halffeat and a feat level for a full feat for a substantial race feature. Find the race skills and institutions separately in the skill level. If further race design space is necessary for special combat, then create a race class. All of these four levels are in the zero levels. They give designers lots of room to flesh out a race or culture concept. At the same time, the result will moreorless balance alongside standard 5e characters.