Placement of illustration: before/after text? I've been reading conflicting advice on SE about the placement of an illustration (figure, table, algorithm). My questions are thus (refer to Section 3.3.1 in the attached figure): 


I understand that, ideally, an illustration should always be placed inside the section where it is first referenced. Should an illustration always be placed in a section after it is referenced? Could it be placed in the same section before it is referenced? 
Can an illustration be the last entity in a section (as shown in Section 3.3.1)? Or does there need to be text after it, such as a short line on what is to be discussed in the next section?


Thanks!
Figures always go after the first reference to that figure. 
Figures always have a caption. In almost all styles captions go after the figure, but before tables. 
Having a figure as the last thing in a section looks a bit odd and you might want to stick in an extra sentence just so it doesn't look odd. Having said that- you can avoid this by not dividing the text very finely (that is, no sub-sub-sections).