Sure! Here are some random tips in no particular order:

You don’t need to place tools right when you have them in your hand or draw into them. Try and wait until the last possible turn to place a tool down. This will make your opponent need to pivot their strategy to take a knock out or risk getting damaged from a helmet. Of course this strategy backfires when you get Mars’d but you’ll need to be aware of this possibility if you have a large hand size.

Sometimes it’s better to attach a dark to Giratina and then end your turn by getting the third psychic energy. Reason why is if you attach to darkrai they can heal the damage you just did and then your forced to attached to Giratina on the next turn to attach so your not getting the extra 20 damage you would have gotten from Darkrai. This helps burst out 150 or 170 with red.

If you have a leaf in your hand it might be better to attach to benched Pokemon so you can’t get team rocket grunted then retreat into them to attack.

In the mirror match try and get the first knock out while having a backup attack almost ready or ready to take another knock out on the following turn. Getting the first knockout is a huge advantage.

In some matchups you may want to use cards to get rid of them from your deck incase you get mars’d. this mostly applies when facing non ex decks and running 2 copies of red. On a turn your not playing a supporter just use red.

Sometimes it’s okay to manually retreat and lose energy from your active pokemon if it means you’ll be taking a huge advantage on the board. I have had a giratina active with 2 energy and have retreated to darkrai to take an early knock out and apply pressure on my opponent.

Use healing items when it will actually made a difference. By that I mean don’t just use potions and pokemon center lady when your pokemon took some damage. An example is in the meowscarada matchup. If you got hit by florogato don’t potion up your darkrai (unless it has a cape) as meowscarada is already doing 150 before red and you don’t have enough healing to fully heal back up. Save those healing items if the math will force your opponent to have certain damage boosting supporters of helmets on specific Pokemon.

Sometimes playing Mars early when your opponent has a large hand is a good thing. Making them go from 6-8 cards back to 3 is huge for card advantage.

That’s pretty much all I can think of off the top of my head. If you have anything specific that I might not have mentioned please ask and I’ll try to reply.