On the home tab of your #Excel sheet or shortcut key Alt, H, L.
You can use conditional formatting to simply highlight values of interest. See this post.
Other options from within Conditional Formatting are, Data Bars, Colour Scales and Icon Sets.
Data Bars
Within Data Bars, you get two Standard options: Gradient Fill, and Solid Fill. What the data bars do, is look at the data you have selected and then fill in the cell with colour. The cell with the biggest number will have all the cell filled, the cell with the smallest number will have a tiny fraction of the cell filled. If you change the value of a cell the colouring will update automatically.
It is a great way to visually see the relative size of your numbers very easily.
There are different colours to choose from, or select More Rules.. to get a range of further options. More on that below.
Color Scale
Color Scale gives you 12 standard options to choose from. What color scale does is to color your cells based on their value. The lowest number will be given one colour, the highest value will be given another colour. The numbers in between will be given a shade between the top and bottom colour. You can also choose 3 colour systems which will set the top, middle, and bottom colours/numbers and transition between them.
Icon Sets
Icon sets can be used to replace your numbers with symbols. Arrows, coloured circles, ticks, etc.
The basic options will split your data evenly between the number of symbols selected.
For example, if you choose green dot, yellow dot, red dot (traffic lights) then values in the top 33% will get a green dot, the middle 33% will get a yellow dot, and numbers in the lower 33% will get a red dot.
More Rules…
Selecting the More Rules… from any of the other sections will allow you to customise the formatting. You can change the colours, the numbers that match to which icon, whether the data determines the minimum or maximum values, and a whole range of other things.
Whatever you are trying to make stand out in your data, consider using conditional formatting to achieve it!