Ok here goes,
1.Use the outline tool to draw a simple square with more vertices for one of the four corners as shown below! TIP: Using the gridsnap feature in the bottom left if very hand here!
2.In the "Vertex select mode" select the second to last two vertices using shift click, its quite important you only select these two for now!
3. Begin resizing the vertices and moving them about and you have a nice looking curve! its easier than you think! TIP: switch OFF gridsnap to get a smoother curve!
4. This is where it can become tricky, still in Vertex select mode, select each verticed 1 by 1 in a clockwise motion, with that select the Vertex Menu > Create Ordered Surface,
with this select "object select mode" and select the object menu > Optimize surfaces.