You can add some styling tags to some labels on a donation form. To do so:
1) Open the form in the admin
2) Locate the Customize Headings and Labels button for the label you want to style
4) Locate the specific label parameter for the label you want to style
5) Add your HTML tag to the beginning and end of the field. For example: ``For a One Time Donation please consider giving`` would be changed to ``<strong>For a One Time Donation please consider giving<strong>``
6) Save or Apply the form.