Step 1:  File> New or Ctrl + N

Step 2 :Creat a new Layer.

Step 3: Click on the Gradient Tool.

Step 4: Pick any color of your choice but make sure it is bellow the white one.

Step 5: Change Shape on from Linear to Radial

Step 6:  Click and hold on your mouse starting from somewhere in the middle and going out to any of the four corners. then realese.

and you should get this

Step 7: Add in you person and adjust the size you want the person or people to be and put them in place.

Step 8: Add title. Also to make  it look more professional right click of the text's layer and click on Alpha to selection Which will trance you words.

Step 9 : your text will be outlined but dotted lines. 

Now you go to Select > Grown and write in 5.

The example has 3 written in though.

Now that that is done.
Make a new blank layer below you Text's/Title's layer Choose a colour. Then click on the inside of the dotted lines around you words to get this.

Second to last step: Make a new layer under everything except the radial Grandient. This is for your funk designing with the brush took . This is what I did.
I used start brushes.

And lastly Write the Designers name A.K.A You and also who the poster belongs too.
I usually just write Storyline by Example.. when no one owns them.