To get things higher you can use tables, but to be able to stack more tables you have to be standing higher. Compare it to real life, lets say you wanted to put something on your roof. Well you can't reach your roof from the ground, but if you were standing on some steps or a ladder you woud be able to reach. So you can use a ladder or goza mats to stand higher and be able to place things. This works for stacking tables as well. You can only stack three of them then they are too high, but if you stand higher up you can stack more on top of them, which allows you to place things on the tables much higher.
Stand on a ladder next to your work area (east or west facing one tile away from steps), stack four tables and drop the stuff on the tables. You can also use a goza elevator to raise yourself high enough to place things high (this is why I recommend using a ladder). So you need to place a goza, raise it up 2 times, place another goza next to it and raise it up by four. Walk on the 2 high goza then the 4 high goza. Raise the 2 high goza 4 more times, step on it. Raise the other goza 4 more times, etc. This way you can lift yourself up in the air. Once you are high enough you can drop things and they will be able to get high enough. So you would stack 4 tables or so and put the item on the top table, then remove the second highest table, then the rest of the tables.
If you weren't next to the step I'd just recommend using a ladder to do it all - you can stand on a ladder, place a trash barrel up in the air, then put all the stuff you need in the barrel and axe it and the ladder.
I should just do a picture tutorial about high stacking. My image server is down right now though, need to get my husband on that.
