These tactics were designed to help you, not hurt you. If you feel that one of these tactics does not work for you, then don't use it.
We all know to move up to a wall when Missiles are coming, but what about shooting from cover?
Typically people move their bots sideways from cover, fire, then move straight back to cover as below:
This isn't very effective. Why? Because as you move from cover and shoot, you expose all of your bot, the bot comes to a stop, the legs turn, then you start to move back to cover. In this time you are exposing yourself to return fire and if you are a light vs a heavy, this is bad news! Aphids will also deal full damage to a light bot as it stops to step sideways again, so you want to avoid this.
Peeking is the correct way to use cover and can allow you take down much stronger and healthier bots.
With this method, you start a little distance from the cover and walk in a circle whilst facing the enemy. You aim to have just the side of your bot stick out of cover as you are walking the circle, meaning you can fire the side weapons with almost nothing of your bot exposed. As your robot is constantly in motion, it never stops so you can quickly get to cover again.
Peeking works with any bot and is very effective with bots that have weapons sticking out on one side, such as a Cossack, Boa or Golem.
You can see around the corner by turning your robot to the 60 degrees away from the corner. Using this, you can see the enemy at the very edge of your screen without them seeing you. However, this leaves you vulnerable to incoming splash attacks.
When someone peeks around a corner, they are mostly protected from projectiles but are still fully vulnerable to splash damage. Thus rocket setups such as death buttons can take advantage of unsuspecting peekers to score massive damage. It is not advised to fire around corners if the enemy has rocket weapons.
Sneaking up to a peeker with a fast knife-fighter can be very effective, as they will most likely have all of their attention and ammunition on their target.
Ever wondered what those two brackets on the side of your screen, whenever you're wielding a missile weapon do? Well now you can take advantage of that and move your robots body to curve the missile and hit enemies behind cover. This may be more effective with Spirals and Hydras than Aphids, as smart jumping bots may be smart enough to actually move/jump out of the way. When doing this (Aphids) against peeking dash bots, you just might have a better chance at hitting them as their reaction when dashing is slower than jump bots such as Cossack, Rogatka or Griffin.
Using vertical obstacles
On some maps such as Springfield (buildings at one of the spawn points) or Dead City (hills at the left side at either spawn point), there are obstacles that are just high enough to hide the hull and expose the weapons. Robots that mount their hardpoints towards the top include the Fury (all 3 hardpoints), Carnage (all 2 hardpoints), Butch (when the second set of weapons are used), Rhino (top 2 medium hardpoints if Assault mode is not activated), Gepard (top hardpoint), and much more. This allows the robot to expose only these weapons and start firing without exposing the hull, and more importantly, if the obstacle is thick enough, it can protect you from some splash weapons. To use this cover effectively, position the weapon(s) directly at the top of the obstacle, but not blocking its fire angle. The Zeus is an excellent weapon for this strategy as the lightning from that weapon doesn't always travel in a straight line, and may angle above the obstacle.
The downside of this ability is that if you do manage to get your robot in such an obstacle, you are still exposed to flanking (unless you have another friendly robot protecting it). Thus, anyone can sneak behind you and fire at you before you have the opportunity to respond to that sneak attack. This is especially devastating if you are an idle sniper and that you just fired off a Nashorn, Kang Dae, or Trebuchet round and you need to reload, as you would most likely not have enough time to get another round and fire it off or find a new cover.