The easiest way is to do a custom CSS. make a child theme first i recomend this plug in “Child theme configuration” Down load the zip file once you chose your settgings. upload the child theme through dashboard> appearance > theme > add new then use a text editor and make a style.css for your theme (bbpress will be overridden with it) I use eclipse for a text editor but notepad will work in the style css add this code
(this came directly from my site so it has a few changes you can change anything you like on it for more customization) you can see my forums lay out here
#bbpress-forums .bbp-forums-list li {
display: none !important;
min-height: 50px;
font-size: 18px;
border: 3px solid black;
border-top: 8px solid #871A1A;
boder-bottom-left-radius:5px;
boder-bottom-right-radius:5px;
boder-top-left-radius:5px;
boder-top-right-radius:5px;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
margin-top: 10px;
margin-bottom: 10px;
}
.bbp-forum-title{
display: block !important;
font-size: 22px;
font-weight: bold;
border-top: 15px solid blue;
boder-top-left-radius:5px;
boder-top-right-radius:5px;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
margin-top: 10px;
margin-bottom: 10px;
}
.bbp-topic-title {
font-size: 16px !important;
}
Like I said any of these values are changeable and you can add more or take some out. hope this helps.