"I have tried twisting them myself but I end up so tired and give up halfway. My hair is very soft and sometimes have to use black strings for the locks to form. Help"
Twisting your locks without a loctician is not easily and more so if you have lots of soft hair.
First of all, if you have lots of hair I could suggest you get a friend who also has locks and take turns to twist each other's locks ie they do yours and you do theirs that could be either fortnightly or monthly. It's easier to twist someone else's hair that it is twisting your own. The only disadvantage to this is that you become dependent on the other person. You could also try dividing your hair maybe into 4 sections and do one at a time. Rest between twisting each section. It will take long but atleast you won't feel pushed for time. I would suggest you also twist when you have time eg on Weekends because then you don't feel rushed. Twist your locks as you do something else like watching a movie or listening to your favourite music or hanging out with friends, keeps your mind away from the twisting, you won't even realize when you finish ( as long as you don't get carried away and forget about twisting as you tell jokes/dance)
As for the soft hair, you could try and use olive oil/ beeswax/ light gel to hold the newly twisted hair. Don't use petroleum or heavyweight products as they cause build up in the lock. Don't fight to have all the newly grown hair in the lock, or to hold it up. I remember when I started twisting my own, I would get frustrated because I have very soft hair, I would twist and I wasn't able to hold every single hair, so I started twisting with gel and holding them up with a clip till they dried, but I soon realized my locks were thinning and my hair was breaking...Just relax, twist the lock with gel/wax/oilive oil then let them dry on their own, the hair that is not held is probably not ready to join a lock yet, give it time next time maybe it will feel like it.
Hope I helped....