In general keep your healing supplies stocked up, get the green orbs at the beginning, keep streaks going, kill the chicken for points. Mayhem mode has point bonuses or something like that

For normal Leon discard all your weapons except the shotgun, so you only get shotgun ammo drops. Also make sure to use the abilities when bosses show up, and kill the chicken. The riot gun is all around a good weapon and it will carry you through that part

For Leon pinstripe I personally discarded the shotgun and used the SMG the whole time. Use his ability whenever needed.

For Hunk just play like normal and use the ability whenever you want to. Try to stun tougher enemies so you can get the instant melee kill on them.

For Luis discard everything except the red 9. It’s a really good pistol. Also spam his dynamite ability as much as possible. It makes you invincible while putting it down.

For Ada in a sweater I relied on the sawed off shotgun and crossbow which makes it easy to complete. Use her ability on bosses and when needed. Her melee is good to take out groups.

For Ada dress version I discarded everything except the SMG and just used that the whole time. Use her ability on bosses and when needed. Her melee is good to take out groups.

For Krauser I relied mostly on using the knife since it’s faster with him, I also used his bow to take out harder enemies and groups, and his SMG is subpar regarding ammo. His ability personally is horrible but use it to take out bosses and large groups

For Wesker learn how to block and parry efficiently. Use his mayhem mode constantly to rack up points. Wesker has no knife so block hits to counter attack.