1. 

   Scale vs. scale

   In Sketch there are two ways to scale layers. The most obvious possibility is to select the layer and drag the handles to the desired size.
2. 

   Link styles

   You know these days, when a client asks you to change all the buttons in your mockup from green to red. With a bit of consideration this problem can be quite easily solved in Sketch with its ability to link styles.
3. 

   Rotate copies

   One of the rather hidden yet very useful not to say terrific features of Sketch is the ability to take a shape and rotate it several times to get different compound shapes or patterns.
4. 

   Copy CSS attributes

   Did you ever wish there was an option in Photoshop, which allows you to copy the visual properties of a layer like the roundness of the corners, the gradients and the shadows to use in CSS? Bad luck for you then. Fortunately Sketch can produce relief.
5. 

   Round to nearest pixel edge

   When you edit the vector points of a shape it can happen easily that the edges are not pixel-perfect anymore.
6. 

   Make Grid, part 2

   Additional to the tip Make Grid, part 1, this option also allows to make copies of a single layer with even spacing. First select the layer which you want to copy and distribute.
7. 

   Switch between color spaces

   A feature in Sketch I've long overlooked is the ability to switch between the standard color space RGB and HSB (normally called HSL).
8. 

   Vector point options

   The different points of a shape the vector points have different modes, which let you define how a point looks.
9. 

   Mathematical operations in input fields

   Input fields are pretty clever in Sketch. They let you perform mathematical operations like 342*2 or 209-2. The operation is performed on the selected layer(s) as soon as you press enter.
10. 

    Edit vector points

    Since every shape consists of multiple vector points, you can also edit them. After you have selected the shape simply press enter or double-click on it to edit the points.
11. 

    Quickly create shapes

    Since the most important feature in every graphic program is actually to create different kinds of shapes, Sketch has a handy shortcut for every important one.
12. 

    Show color picker

    This shortcut shows a color picker, which you can use to quickly select a color from your design.
13. 

    Template creation

    When I'm working on an iOS app, I like to use this template by Thierry Teyssier. It displays an iPhone 5 shape around the art board and allows you to easily visualize the design in context at any time.
14. 

    Layer guides

    Sketch automatically shows alignment guides when you move layers around or nudge them with the keyboard. However there are still times when you need to set manual guides to line up layers.