GW Marcher

I will refer to ice wizard as ice wiz, magic archer as marcher and skeleton guard as guard throughout this guide.
General upgrade guide:
Ice wizard: 1>2>3 can be changed if prince to 3>1>2
Magic archer: 3>2>1
Skeleton Guard: 2>3>1 or 3>2>1
Knight: Any order but I like 1>2>3 or >2>1>3
Prince: Doesn't really need an upgrade but remember 3 stuns

Round 1: Get marcher in the corner, if no marcher, place no minis.
Round 2: Upgrade marcher, if no luck again try using the minis you got to counter them.
Round 3: Marcher 3 star and if possible use ice wiz to block in and slow opponent.
Round 4: Prince MUST come to use at opening up/ attacking the opponents carry. This can be done at any other stage. Use guard and knight to get more shields and to distract their minis from your prince.
Round 5: Upgrade your minis and win (hopefully).

Make sure to remember to cycle your minis so that you can get the required ones.

Dart goblin is a hard counter though, so use the prince on that if possible - not right away in case they have a defender.

There is a video, but it is not mine so I have not linked it, however it is called: PUSHING On Ladder To 3000 Trophies In Clash Mini! by Mosi. There is a couple of videos titled this by them though so look for this one. Otherwise, you can watch their pushing decks!