The two biggest tips I'd give to somebody who's starting out on demo would be to
1) De-equip your pipe launcher
2) Get your rollouts/timings down(when I say timings I mean things like "if the scout rolls out this way, he'll arrive here at X time") there is no limit to how useful this can be.
Honestly, there are so many situations where I even see some top level demos using pipes when it would just be so much better if they were reloading stickies.
Of course, pipes are very good and should be used at certain points, but until you think you're comfortable in judging when it's better to use pipes(when you need to defend yourself or teammates in close proximity) instead of reloading stickies you should use something like the bootlegger instead.(thanks zambles)
Traps are overrated, 9 times out of 10 it would be better to be pummeling them with your stickies instead of spamming dodge-able pipes and waiting for them to walk into a trap.
edit: not to say you're "new" to demo, i don't even really know you, just some things to think about