How to change the number of columns:

{block:IfCenterSidebar} .colums{ -moz-column-count: 2; -moz-column-gap: 250px; -webkit-column-count: 2; -webkit-column-gap: 250px; column-count: 2; column-gap: 250px;}.page{ width: 1100px; max-height:100%;} {/block:IfCenterSidebar}

If you’re using your theme with the sidebar on the CENTER, you will change that code. If you’re using the sidebar on the left, look for the code between {block:IfLeftSidebar} and {/block:IfLeftSidebar} and if your sidebar is on the right, look for the code between{block:IfRightSidebar} and {/block:IfRightSidebar}.

Ok, now let’s understand that code:  -moz-column-count, -webkit-column-count and column-count means the number of columns, in the example code, we have two columns.

-moz-column-gap, -webkit-column-gap and column-gap indicates the space, in pixels, between the columns, in the example code, we have an spacing of 250px. 

Remember: always put the same number of columns and spacing.

How to change the size of the posts:

Now, that’s a complicated part. Firstly, find the code bellow on your theme:

.cpost{width:250px; padding:30px; background:{color:Posts Background}; margin-bottom:30px; display:inline-block; text-align:justify;}.cpost2{width:250px; padding:30px; background:none; margin-bottom:30px; display:inline-block; text-align:justify;}

Change the WIDTH (of .cpost and .cpost2) for a desired value. I recommend 250px, 400px or 500px. Right below this code, you will find one “blockquote”, change the width of that one too (I recommend that you put the .cpost width less 50px).

Now, look for this code:

.tags{position: absolute; margin-left: 240px; opacity:0; border-left: solid 1px rgba(0, 0, 0, 0.3); padding-left: 10px; transition:All 0.5s ease-in-out;-webkit-transition:All 0.5s ease-in-out;-moz-transition:All 0.5s ease-in-out;-o-transition:All 0.5s ease-in-out;}.cpost:hover .tags{margin-left: 290px; opacity:1;}

Change the two MARGIN-LEFT from this code. The first one, put the number of pixels of your post size, less 10px. The second one, put the first value more 50px.

Now, let’s change the images size:

Look for the codes bellow in your theme:

{PhotoURL-250}

{Photoset-250}

{VideoEmbed-250}

The “-250” represents the size of your photo, of your photoset and of your video. Tumblr allows only four sizes for photos (100, 250, 400 or 500), for photosets (250, 400, 500 or 700) and for videos (250, 400, 500 or 700). Use one of those values.

Well, I think that’s all. I hope it was helpful, and sorry for my English mistakes. Any doubt or problem, ask us again!