When ever I go walking on my own i always carry with me as many aids to navigating as I have.
These include map and compass, sighting compass,guide book,and I phone. Over the years I have come to rely on my i phone with an App called 'Maps.me'. You don't need a mobile signal to use it and it has all the paths and hilltops in its data base. You can also import GPX files into it and use it it to check that your still on the route.Also when ever i get in the mist i will place a few stones on a prominent place so I can always retrace my steps.
However things can go wrong and i have learned the hard way and that using the map is the best..
First off use the map to make sure you set off in the right direction. Setting off the wrong way at the start is common and if you discover that you are going the wrong way you should return to your last known position.
Secondly check the map ahead and tick off things as you pass them. Look on the map for well defined locations that you can head for. If you can get to a known spot like a trig point or a sheep fold or even a point where a wall changes a sharp angle then you can take a bearing to another defined spot. Staying on a bearing can only be done by sighting something on the ground along the bearing and walking to it. Once you do this you can take another bearing to some other spot along the bearing.
Walking in mist can be worrying and the more things you can identify the more confident you will be. I once came over Bleaklow in thick mist and even though i was sure where i was i looked at the map and saw that a farm was the next location i would pass.The farm was about one and a half miles away but eventually i started to hear a dog barking and as I got closer another dog joined in. As i came down out of the mist i could see the farm ahead with the two dogs still barking.
Also learn what things on the map actually mean.On the OSGB maps there are green dotted lines all over and it can come as a surprise to find that sometimes theres nothing on the ground when you get there. Sometimes when route finding you may see a wooden footpath sign in the distance and when you get there it only says footpath and not where to.Pretty useless really!.
If you do manage to find a footpath sign with a destination on it then make sure you actually walk in the direction its pointing. I saw two guys on the Pennine Way using a GPS. I was stopped next to a PW sign and it pointed across some ground where there was no path visible on the ground. The two guys ignored it and set off the wrong way along a slender path. I watched them for a few hundred yards then they veered off across open ground to rejoin the proper path.
If your walking in a group its a good idea to let one person navigate. I walk regularly with a guy who loves to use his maps. I call him half man half GPS. He may not always be right with his decisions but I never interfere and we always get to the pub.
If you use your experience and keep your eyes open then you wont be worried when faced with a view like this..