You can find the point cloud properties in the Project menu, access it by clicking the point cloud you wish to modify in the Point cloud sub-category in the Object category.
First the point size, you can change the point size for each seperate point cloud, this goes between 0 and 3 but don't worry a size of 0 wont let the points disapear.
Point size minimum :
Point size maximum:
Secondly you can change the method, this affects the overall look of the point cloud, fixed being the default look, you can then select attenuated, this gives the points a small size overriding your point size settings and finally adaptative, this one modifies each point to complete every hole between points, this means points will get bigger so they touch each other. When looking from a distance, the last one will usually give the best result but when closing up you will want to switch to another method.
Method fixed :
Method attenuated :
Method adaptative :
Third option, the point shape, you can choose between 3 point shapes, squares (default), circles and paraboloid.
Point shape square :
Point shape circle :
Point shape parabloid :
The opacity is once again pretty self explanatory, change the value between 0 and 1 to change the point cloud opacity, from hidden to perfectly visible.
Opacity 0.04 :
Opacity 1 :
But we are not done with the options because with these new options came a new category, the Attribute category, this category give much much more options so you can get to the perfect render for your point cloud. At the top of the category you will find a select menu, here you have 15 options, each option will display a sub-category proper to it with more options. To learn more about attributes please check out the Point cloud attributes article.