diff --git a/readme.md b/readme.md
index b4b5209..d6c0722 100644
--- a/readme.md
+++ b/readme.md
@@ -38,32 +38,34 @@ We create an object from the class or helper where we define the configuration u
 1. The `compound_variants` keyword argument where we declare the compound variants with their conditions and classes
 1. The `defaults` keyword argument (optional) where we declare the default value for each variant.
 
-## Example
-
-Below we implement the [button component](https://tailwindui.com/components/application-ui/elements/buttons) from Tailwind UI.
+Below we'll implement the [button component](https://tailwindui.com/components/application-ui/elements/buttons) from Tailwind UI.
 
 ```ruby
 # Define the variants and defaults
 button_classes = ClassVariants.build(
   base: "inline-flex items-center rounded border border-transparent font-medium text-white hover:text-white shadow-sm focus:outline-none focus:ring-2 focus:ring-offset-2",
   variants: {
+    color: {
+      indigo: "bg-indigo-600 hover:bg-indigo-700 focus:ring-indigo-500",
+      red: "bg-red-600 hover:bg-red-700 focus:ring-red-500",
+      blue: "bg-blue-600 hover:bg-blue-700 focus:ring-blue-500",
+    },
     size: {
       sm: "px-2.5 py-1.5 text-xs",
       md: "px-3 py-2 text-sm",
       lg: "px-4 py-2 text-sm",
       xl: "px-4 py-2 text-base",
     },
-    color: {
-      indigo: "bg-indigo-600 hover:bg-indigo-700 focus:ring-indigo-500",
-      red: "bg-red-600 hover:bg-red-700 focus:ring-red-500",
-      blue: "bg-blue-600 hover:bg-blue-700 focus:ring-blue-500",
-    },
+    compound_variants: [
+      { color: :red,  border: true, class: "border-red-800"  },
+      { color: :blue, border: true, class: "border-blue-800" }
+    ]
     # A variant whose value is a string will be expanded into a hash that looks
     # like  { true => "classes" }
-    block: "w-full justify-center",
+    icon: "w-full justify-center",
     # Unless the key starts with !, in which case it will expand into
     # { false => "classes" }
-    "!block": "w-auto",
+    "!icon": "w-auto",
   },
   defaults: {
     size: :md,
@@ -78,7 +80,7 @@ button_classes.render
 button_classes.render(color: :red, size: :xl, icon: true)
 ```
 
-### Compound Variants
+## Compound Variants
 
 ```ruby
 button_classes = ClassVariants.build(
@@ -100,6 +102,172 @@ button_classes.render(color: :red) # => "inline-flex items-center rounded bg-red
 button_classes.render(color: :red, border: true) # => "inline-flex items-center rounded bg-red-600 border border-red-600"
 ```
 
+## Override classes with `render`
+
+We can also override the builder classes in the `render` method.
+
+```ruby
+button_classes = ClassVariants.build(
+  base: "inline-flex items-center rounded",
+  variants: { ... },
+)
+
+button_classes.render(color: :red, class: "block")
+```
+
+Now, the `block` class will be appended to the classes bus.
+
+If you're using the [`tailwind_merge`](#tailwind_merge) plugin it will override the `inline-flex` class.
+
+## Block configurations
+
+You might have scenarios where you have more advanced conditionals and you'd like to configure the classes using the block notation.
+
+```ruby
+alert_classes = ClassVariants.build do
+  # base
+  base "..."
+
+  # variant
+  variant color: :red, class: "..."
+
+  # compound variant
+  variant type: :button, color: :red, class: "..."
+
+  # defaults
+  defaults color: :red, type: :button
+end
+
+# usage
+alert_classes.render(color: :red, type: :button)
+```
+
+## Slots
+
+You might have components which have multiple slots or places where you'd like to use conditional classes.
+`class_variants` supports that through slots.
+
+```ruby
+# Example
+
+alert_classes = ClassVariants.build do
+  # base with slots
+  base do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # variant with slots
+  variant color: :red do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # compound variant with slots
+  variant type: :button, color: :red do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # set defaults
+  defaults color: :red, type: :button
+end
+```
+
+```erb
+<div>
+  <div class="<%= alert_classes.render(:head) %>">
+    Head of alert
+  </div>
+  <div class="<%= alert_classes.render(:body) %>">
+    Body of alert
+  </div>
+</div>
+```
+
+## Full API
+
+```ruby
+# Configuration
+alert_classes = ClassVariants.build(
+  base: "...",
+  variants: {
+    color: {
+      red: "...",
+      black: "..."
+    },
+    type: {
+      button: "...",
+      link: "..."
+    }
+  },
+  compound_variants: [],
+  defaults: {
+    color: :red,
+    type: :button
+  }
+) do
+  # base without slots
+  base "..."
+
+  # base with slots
+  base do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # variant without slots
+  variant color: :red, class: "..."
+
+  # variant with slots
+  variant color: :red do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # compound variant without slots
+  variant type: :button, color: :red, class: "..."
+
+  # compound variant with slots
+  variant type: :button, color: :red do
+    slot :head, class: "..."
+    slot :body, class: "..."
+  end
+
+  # option 1 (my favorite)
+  defaults color: :red, type: :button
+
+  # option 2
+  defaults do
+    color :red
+    type :button
+  end
+end
+
+# Usage
+
+# renders the defaults
+alert_classes.render
+
+# render default slot with custom variants
+alert_classes.render(color: :red)
+
+# render slot with defaults variants
+alert_classes.render(:body)
+
+# render slot with custom variants
+alert_classes.render(:body, color: :red)
+
+# if slot not exist, throw error? return empty classes?
+alert_classes.render(:non_existent_slot, color: :red)
+
+# render default slot with custom class (will be merged)
+alert_classes.render(class: "...")
+
+# render slot with custom class (will be merged)
+alert_classes.render(:body, class: "...")
+```
+
 ## Use with Rails
 
 ```ruby
@@ -135,6 +303,36 @@ end
 <%= link_to :Avo, "https://avohq.io", class: button_classes.render(color: :red, size: :xl) %>
 ```
 
+## Helper module
+
+If you're developing something more complex you might want to use composition more. You might want to use the helper module for that.
+
+```ruby
+class MyClass
+  include ClassVariants::Helper
+
+  class_variants {
+    base: {},
+    variants: {}
+  }
+end
+
+MyClass.new.class_variants(:container, color: :red, class: "shadow")
+```
+
+## `tailwind_merge`
+
+By default, the classes are merged using `concat`, but you can use the awesome [TailwindMerge](https://github.com/gjtorikian/tailwind_merge) gem.
+Install the gem using `bundle add tailwind_merge` and use this configuration to enable it.
+
+```ruby
+ClassVariants.configure do |config|
+  config.process_classes_with do |classes|
+    TailwindMerge::Merger.new.merge(classes)
+  end
+end
+```
+
 ### Output
 
 ![](sample.jpg)