I've developed a trend of ALWAYS nicknaming my Pokemon (I even have a whole Microsoft Word document set up for just this purpose, but mainly for if ever my save file gets wiped and I forget nicknames), mostly due to the argument of "calling a Pokemon by its original species name is like calling all of your friends 'HUMAN' all the time when trying to get their attention." Thus, nicknames are applied just like humans have given first names and pets have given names, in order to differentiate between members of the same Pokemon species and provide an iota of personality to them. :)
The only Pokemon that I will never nickname are legendary Pokemon (Uxie is the exception. When I first saw its name I misread it as "UXLE", not "UXIE" (must have been the lowercase "L"/uppercase "I" confusion with certain fonts), and got disappointed when I learned it's true name. I was like "UXLE (I pronounce it "ooks-lay") sounds way better than Uxie!")
The reason? The first time I caught a Latias :t380: in elementary school, me and some of my friends began brainstorming for a name. The best we came up with was "LT. STAR" (as in "Lieutenant Star"). So yeah... Don't ask. :cer_laugh: In short, because of that odd but funny incident, all legendaries bar "Uxie" so far will keep their original names, which is why I always hope they sound cool.
I name my Pokemon in uppercase. I tried the lowercase thing once, but it looked way too weird, especially in the summary screen when you see the lowercase nickname to the uppercase species name all the time. Plus, all of the proper nouns and names of people, places, and things were all in uppercase, so I just followed suit. Though I assume it'll look weird when seeing virtually everything in DPPt/HGSS in lowercase, with nicknames and species names being the only things that can be rendered in uppercase. I don't mind though; it's fun "yelling" your Pokemon's name! :D
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I had originally started a trend where my starters would all have the "-er" suffix in their nicknames:
Charizard: Flamer
Blastoise: Blaster
Venusaur: Forrester
Raichu: Volter/Charger
Typhlosion:Flarer
Feraligatr: Feraller
Meganium: Leafer? (really had trouble)
Blaziken: Blazer (first ever nickname I devised!!! :))
Swampert: Swamper
Sceptile: Razor (exception)
Infernape: Breaker (reference to fighters typically breaking stuff)
Empoleon: ?????????? (had trouble, but in retrospect I might've picked Emperor)
Torterra: ?????????? (had trouble as well)
...But this later seemed tacky/too forced in my opinion, so I scrapped the "-er" theme and changed it up to just standard nouns, etc.:
Charizard: Wildfire (stemmed from Blast Burn animation)
Blastoise: Blaster, Blast Boss, or BlastrBoss (undecided)
Venusaur: Venom (stemmed from "Venu-" prefix which seems to actually come from Venus. But whatever! :rambo:)
Raichu: Lightning (for now)
Typhlosion: Override
Feraligatr: Thundrclap (from Totodile clapping so dang much {albeit in a cute manner} in the anime! :))
Meganium: Vitamin C (reconsidering as it has nothing to do with oranges really, but shiny variant is more 'convincing' in coloration)
Blaziken: [Trail]Blazr (originally going to be Blazer as he was my very first Pokemon. I lost 2 Sapphire cartridges and an Emerald save file. So, the "Trail" prefix represents that no matter the trials and tribulations, Blaziken and I will keep on chuggin' trailblazing through our Pokemon battles and adventures, persevering! :D :t257: The most meaningful name I've come up with so far, and the main reason I'd like a shiny Blaziken! :cer_boogie: (the colors IMO evoke a more powerful, experienced Blaziken)
Swampert: Swamper, Hammer, Slejhammer (undecided)
Sceptile: Razor or RazorBlade (undecided; leaning more towards Razor. Any shiny version I manage to receive later on will get nicknamed Knifejaw)
Infernape: Crossfire
Empoleon: Hatchet or Larry {01} (leaning more toward Hatchet. Derived from Steel-typing, apparent resemblance of a hatchet weapon for some reason, and from the term hatch relating to birds. Larry (-01) is derived from the name of one of my high school dorm mascots, which coincidentally turned out to be a penguin! Larry (01 suffix being optional) might be what I spell out using PokeBall seals, though)
Torterra: Forrester (seemed more fitting considering the epic MASSIVE forest on its back; derived from Venusaur's original nickname)
Enbuoo: Razorback (cool alternate name for boars; but IMO it'll look awkward whenever sent out with my Sceptile :()
Daikenki: possibly Daikenki if English names turns out to be Samurotter or something different (Daikenki is fun to say IMO and has "dai" prefix meaning great/big. Also, kanji relates to fire, evoking a samurai otter that uses water with a sheer ferocity that is equal to that of a flame. :D)
Jaroda: Poison Ivy (poison stemming from snake attribute; ivy relating to plants)
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Hmm...that's all I can say for nicknames from my personal experience. They're very fun to come up with, though. One of the most memorable/funniest/cutest nicknames I've come across was McShockers the Electabuzz :t125:, which I plan to use when nicknaming my Electivire. :cer_laugh: :laugh: I made a nickname for Magmortar to sort of match McShockers as well, but I can't recall it at the moment...
EDIT: Just remembered the nickname for Magmortar - Berserker the Magmortar :t126:! Mostly relates to the other one by the "-er" suffix... Sounded EPIC for Magmortar, IMO... (Ballistic(s) was one I was considering as well before I settled on Berserker...right now I don't know you to use it on...)