Hat is more like a box.

[Acrthrs]

I'm currently making my first hat. I just finished my first shawl and my cousin asked if I could make hats for her and a friend with a similar motif, but I've never made a hat before. So I decided to make one for myself first so if I screw up, it's only on mine. However  I have run into a problem. I spent 5 hours last night trying a few different patterns and had the same issue with each of them. Once I finished the increasing rows, and started the rest, my hat was very boxy. No matter which pattern I tried, none of them had the nice domed look that the finished picture had. I've tried cloche patterns, beanies and slouch hats and all did the same thing. I've had trouble in the past with accidentally increasing when crocheting, round or flat, so I always mark the beginning or end of the row.

[magiccrochetfan]

Do you mean the top is like a flat circle?  Or do you mean it has corners?  

If it is too flat, you should intersperse a few non-increase rows between the increase rows.  I often have to do this.  

If it has corners, this is because your increases are stacked on top of each other.  Move the placement of your increases to avoid this.