A lot of producers find it hard to arrange their parts together.
One way:
Load a song you like and study how it was arranged (e.g. making notices and setting marks etc.)
My Way:
Go on Beatport/ DJ Tunes or any other Music Portal that lets you see the waveform of songs.
Now use a snipping tool to copy the waveform ( PICTURE!) and paste it into a document!
When analyzing the waveform you´ll notice, where the breakdowns/ buildup, drops etc. takes place in the song and from their you can get and idea/inspiration to arrange your own songs.
Just give it a go!