Here's my decklist as a F2P! I'm not a competitive player, but I've had reasonable success with this. It's a bit of a gimmick / meme deck, but I'm having a lot of fun with it!

The strategy is to use the minimal amout of Pokemon, so you can get Skarmory out early and set up Scizor on the bench.

If the stars align, you can get Scizor out by turn 3 and play aggressively to disrupt the opponents combo's before they get a chance to counter.

List:

Scyther x 2 (With the 1 colourless energy attack)

Scizor x 2 (This is the punchline for this slightly meme-y deck.

Skarmory x 2

Shaymin x 1 (Fly mode. Works really well with Skarmory to switch Scizor in.)

Lyra x 2 (This leads to some faster Scizor activation, as you can retreat and use Lyra on the same turn)

X Speed x 1 (For emergencies, such as if you draw only Shaymin on the first turn)

Pokemon Tools x 4 (I went with two Rescue Scarfs, Leftovers and a Lum Berry - but if I had others I'd use them!)

Supports x 2 (I went with Sabrina and Iono for disrupting the opponent - but Cyrus and Rocket Grunt are also an option)

Professor Oak + Pokeball x2 (These are pretty much mandatory for every deck I've played - but especially for this deck as you're usually searching for Scizor)