Okay, so my problem is, that I have difficulty visualizing graphs of functions.  

For example, if we have to calculate the area bounded by multiple curves, I face difficulty in visualizing that how the graph would look like. And in Integral Calculus, it is very important to plot the graph in some problems, so how can I improve my visualization skills? What can I *implement* in my daily math problem solving to improve these skills?  

**Edit**:I am not talking about normal functions, simple ones like Signum function, absolute value function etc. I am talking about more complex ones like 
\begin{equation\*}
y=e^{|x-1|+|x+2|}.
\end{equation\*}