I would normally start in centre and work outwards otherwise you can trap air.
Hot air guns are better than flame but care is required not to over heat. Especially at the ends as it can split if over heated.
Needs to be as even as you can there are tools to assist this that force heat around shrink not just at one point but not found the too good.
As with soldering, welding, it's practice that makes perfect and everyone over heats some shrink at some time.
It also shrinks end to end which is why I start in centre it is so easy to end up with gap between shrink and outer sheaf and one has to be very neat.
The shrink joint has given way to the cast joint which is easier unless it leaks. Some extra self amalgamating tape is handy plus of course has to be level which is where shrink has the advantage.
As to crimping the Hydraulic are easy as you select dies and pump until it auto releases in main but the adjustable strong arm type can be hard and I have needed to slack off and crimp twice when getting near the 120mm limit of my set.
Foot operated hydraulic crimps are better than hand type as with hand type head and pump are in one and can be hard to position.
With oval dies used with tap off crimps you need to be careful to orientate correctly.
