On the other hand, there are some really interesting and creative designs
Charmeleon (Mega Shine) is not available in Regular Packs
Flower Cardian is an interesting archetype that revolves you being able to draw additional cards in your turn
Arcbound Bruiser Arcbound Condor Arcbound Crusher Arcbound Fiend Arcbound Hybrid Arcbound Javelineer Arcbound Lancer Arcbound Mouser Arcbound Overseer Arcbound Prototype Arcbound Ravager Arcbound Reclaimer Arcbound Shikari Arcbound Slasher Arcbound Slith Arcbound Stinger Arcbound Tracker Arcbound Wanderer Arcbound Whelp Arcbound Worker Blaster, Combat DJ Blaster, Morale Booster Modular Monstrosity Power Depot Scrapyard Recombiner Zabaz, the Glimmerwasp
Start by identifying your focus, whether its EX Pokmon, Trainer cards, or promos
Your core idea can be as simple as giving your own take on a popular card or as complex as designing around fulfilling a game-breaking combo you discovered (for example, a Zarude-V [VIV] healing loop with Starmie [EVO] I used in a tournament with only three sets legal: Evolutions, Guardians Rising, and Vivid Voltage)