As you have most likely discovered, Winforms Textboxes do not have a padding property. Since Panels do expose a Padding property, one technique would be to:
- Create a Panel
- Set its border to match a Textbox (e.g., Fixed3D)
- Set its background color to match a Textbox (e.g., White or Window)
- Set its padding to your satisfaction (e.g., 10,3,10,3)
- Add a Textbox inside the panel
- Set the Textbox’s border to none
- Play with the Textbox’s Dock and Anchor properties do get desired effect
This should get you started. You could also create a custom control that does the same thing as mentioned above.
In case you were talking about Textboxes in asp.net, just use CSS:
input[type="text"] {padding: 3px 10px}