One of the easiest ways to get on HF is to find a regional net and check in.
I like using these to get real live feedback on my signal and develop a feeling for how far it will travel in various conditions.
Net check-ins are fast and allow you to hear others in the area, giving you an idea of where you could be talking to at that particular time.
Listen and make note of calls that you hear regularly and note their locations. These will likely be the ones you are talking to in SHTF.
This is good information in itself and I have saved it offline for obvious reasons. Are you developing a folder for possible contacts in SHTF?
Regional daily nets are a great resource, I recommend you start using them now.