During the early stages of the game, your priority is usually searching out Basics to put on your Bench. Rarely will your starting Pokémon be able to win you the game all by itself, even if it evolves into your attacker — you're going to need backup attackers, support Pokémon, or your deck's gameplan might simply not involve attacking immediately, but switching to another Pokémon to set up. This section covers the common options for getting Basics into play.
The default option for most decks. It gets most Basics (Rayquaza ex δ is a notable exception, as it has too much HP), and can get a Holon's Voltorb/Magnemite as Energy too.
The next most common option.
Usually used when your deck is aggressive and wants to attack with its starter instead of retreating to another Pokémon to setup, or when your starter has an attack that can search out Basics.
On average it's equal to Great Ball, but its unreliability can be your undoing if you flip double tails.
Some reasons to use Dual Ball over Great Ball:
You need to search for a Basic ex, e.g. Mew ex.
You need to search for a Basic that must be played from hand (Holon's Pokémon, Pokémon with when-played Powers, Pokémon that must be Baby Evolved).
A double Great Ball (that can get ex's) in Supporter form.
Usually played with Castaway. It's a bit like a slow Holon Mentor: instead of searching out Holon's Voltorb/Magnemite and 2 other Basics, you Castaway for a basic Energy, and a Fan Club which will get you 2 Basics next turn.
More card advantageous than the other options we've seen so far (Lanette is a +2), but has severe restrictions on it. You have to get 3 different types, meaning you can't get duplicates of the same Basic if that's what you'd like.
Note that it says "3 different types of Basic Pokémon", not "3 Basic Pokémon of different types". If you choose one dual-type Pokémon (e.g. Jirachi HL), you can only get one more.
Like Pokémon Fan Club, Lanette's Net Search is usually played with Castaway.
Unlike later formats, in RS-PK, you can always attack on your first turn, so setting up with an attack is a viable option. Dunsparce's Strike and Run is one such example, benching 3 Basics from your deck. It was used a lot in the 2004 format, but sees much less play in RS-PK because Holon Mentor is better.
The main consistency issue is starting with Dunsparce. Since you'll also have other Basics in your deck, you're not always guaranteed to start with Dunsparce, and if you have to spend an Energy retreating and another powering up Strike and Run, you may be too far behind at that point. Swoop! Teleporter can help with consistency.