As for single engine on a twin, follow the qrh (for the 757 it says land at nearest suitable airport).
Good knowledge of non-technical skills will help you (Leadreship, Management, Decision Making, Situational Awareness and Team Work).
Take your time, when I first started I found that I would rush feet first into problems, now I take a deep breath and do things in slow time.
Use of decision making tools such as DODAR and FORDEC are useful.
Just my 5p.