I've got one too. I'll be watching this thread intensely, as I'm at a loss for what to do about a lot of the fourisms myself.
On the tissue thing, I watch my daughter and if I see her dropping things (trash) on the floor I just ask her if that is where it goes. She says no, usually, and then I ask her where it goes or tell her to go put it in the trash can. That one seems to work for us, but it is something I have to do pretty consistently.
As for throwing toys, hitting, or any behavior that physically hurts someone I try to relate it to an experience she's had of being hurt by her peers. "Does it hurt when your friends, throw toys at//kick/hit you? Does it make you sad?" And tell her it hurts me too and it makes me sad too. Relating what she feels when it happens to her to my feelings when it happens to me is usually enough to demonstrate why the behavior is inappropriate. And then I ask her what we should do. She'll usually respond "not throw/hit/kick." And I'll continue the conversation by telling her we can use our words to express our frustration, or we can play with the toys in a different (more appropriate) way (depending on why the behavior is happening). I also reserve the option of putting things away if she's not using them appropriately after she chooses not to stop the inappropriate behavior.
I feel that some behaviors are very appropriate to counter with consequences at this age. Not responding to me when she's watching tv means the tv is turned off. Not finishing one snack she's asked for means she doesn't get the next thing she wants (this is within a single snack time period; she's a food hopper even with very small portions.) Not allowing her to be on the couch if she's standing up on it (we don't treat furniture this way in my house). Coloring on herself/not on her paper means the markers/crayons get put away. Dawdling while getting ready for bed means we can only do one book OR one song before it's time to go to sleep, or neither if she's really been dragging her feet.
I try to make the consequences as natural as possible, but sometimes I get flustered and make them more general. If she's had a hard time listening and complying with my requests all day (you know, so we can actually do anything) then we don't can't have "treat" foods or we don't watch any tv. Because those things really worsen the behavior. With this last one I _try_ not to bribe/reward her (sometimes I do, but nobody's perfect). If she's asking for one of these things and her behavior has been pretty poor all day I'll tell her that we can't do it since she's having a hard time listening today and these things usually make it harder for her, but we can talk about it again later today or tomorrow.
Some of these consequences induce tantrums and if all else fails I ask her to go to her room until she is ready to listen. Sometimes she just needs to regroup and having me around escalates the behavior instead of allowing her to calm down and let go.
ETA: On the hurting issue, it's especially effective if I can relate it directly to an experience she's recently relayed to me of a friend hurting her. More effective than the general "when your friends do X" approach, but the general approach still works when I need it.