all starts have their pitfalls but at end of day the last 4 cards are the most important
I do not recommend starting any situational card. For example diaonchan. If you play her too early you will face treant. Here's some other situational cards.
Trap detect, sabotage, violent maid, lizard man, storm elemental, apprentice swordsman, bandit, royal girl hunter, unicorn, 2 quios.
Now you can in fact start situational cards to with the intent to force the opponent to avoid using certain cards. For example if you start unicorn this may sway them from playing enchanted cards. Storm elemental may sway them from playing spells. If you are playing situational cards like these you have a different pattern and mindset you use and go about each battle.
Some very strong start is to play Devils daughter and succubus Queen. Two situational cards yet synergistically connected.
Some things I tend to avoid doing are such;
1. Two units with same cooldown. Helps avoid reapers
2. Two inits with odd CDs. Helps avoid arrows.
3. Two units whose attack and armor types aren't such that a late diaonchan would cause them to easily kill each other. Remember diaonchan makes your units attack each other.
Note: currently I am breaking rule 3 with my start so I am constantly aware of that fact and have strategies in place to deal with it for my final picks if necessary.
4. Two units less than 9 cd. Dangerous vs arcane blast.
Of course any of the rules can be broken bc all starters have their pitfalls so as long as you know the weaknesses your picks can help u get out of trouble.
Some of the stronger decks I've played lately are theme decks. Starting two blizzards and playing ice elemental heals or priests and magister. This deck will get massacred by wizards power. So just remember to play sabotage vs someone you suspect will play that card.
Another popular deck is to start two blessing of mother earths and four more nature cards. Many like to start a red dragon and finish with two bears. As the opponent throws magic cards to deal with red dragon this gives the bear better odds of defending and surviving.
Some non situational cards that can work just about everytime that people start are;
1. Succubus
2. Red dragon
3. Magister
4. Nine tail fox
5. Skeleton King
6. Priest
7. Joker
8. Blessing of Mother Earth
9. Pit trap
10. Blizzard
11. Hero
12. Junior sorceress
Junior sorceress and regular heal is surprising good especially if your opponent has overplayed magic attack. So you could play this card with another init that requires magic attack to kill like red dragon or ice elemental. That can be a strong combo just watch for wizards there too.
You should experiment with many starts to learn their strengths and weaknesses. That way you also know how to beat those starts when you play them.
Fyi I cutrently start wyrm succubus Queen, slayer Devils daughter, or Jenn monkey king. Many of the top players all have their own starts that are unique to them. So have fun each start requires a different style and I Trieste knowledge of how to play to it's strengths and weaknrsses.