勇往邁進(I found this tiger/Great wave picture and thought it was too awesome not to include it in this post. Look at that tiger, ignoring the fact that there's a giant wave coming and that tigers are not ocean creatures. He's gonna do his best anyway. The pic comes from this blog.)
Pushing forward, without regard for difficulties or distress.
Think of this one as in the same league with 猪突猛進, but without the negative connotation. Use it with する。
I'm not sexist or anything but, some sources also translate this yoji as: effeminacy. Hah. Use it as a な adjective.
Thoroughly, completely prepared, having left nothing out.
Maybe you could think of this along the same lines as one of the two interpretations of 正々堂々？ You can use it as a な adjective, or with に。A 用意周到な旦那 is not necessarily a 亭主関白, but a dude could be both, right? A 四角四面 guy on the other hand, would definitely like this 四字熟語。