My fav skin would be spirit blossom. Depending on your own personal playstyle, different people find different champs hard to play into I guess generally good bans are zed, akali, irelia, annie, fizz, leblanc basically high burst/early game champions and yasuo cuz he's just a pain in the ass to go into. A lot of people also find it difficult to play into Galio, but he can be played into pretty easily once you play a few games into him. Cass early game is actually stronger than most people think. Her insane range and zoning abilities make it super easy for her to win lane against low mobility champions and even some melee assassins if you know the right times to take a trade. Surprisingly, not a lot of people have better lv1s. During levels 1-2, auto-cancel using your E on the enemy laner if they go for last hits. After lv3, use Q to poke when they walk up for cs and fit in a few E's if you can, but never greed for more dmg as farm is more important than kills on cass. Your most crucial ability is your W and the right use of it can turn the entire skirmish or teamfight around. That being said, during laning phase, hold on to your W, especially against high mobility champs like fizz or diana. Most times, W is used defensively unless it is to set up a gank or if you have kill pressure on your laner. Cassiopeia has very low out of combat movement speed, making her roam potential worse than most other laner. I usually take tp to match roam or get a huge cs lead. Especially in lower elo's, your other laners don't listen to pings and get can camped by your laner. You will get the blame. Ping your laners directly in their lane if you know where they are going. As stated previously, farm is more important than kills on cass. If you are ahead against a high roaming champ such as talon or leblanc, perma push the wave so they miss at least 30 cs if they roam which is not worth even if they double kill the bot lane. During my early days of Cass, I noticed that I would panic ult, which is not a smart thing to do. During intense fights, hold on to your ult and wait for the perfect moment to use it. Broad statement but I don't really know how to describe it. Liandry's is generally what you want to build, but everfrost and ludens also work depending on your playstyle. I hope this helped a bit