Just typed a really long post then lost it so will kep this brief
excuse typ[ing - feeding ds2
ds1 used to be a joy if loud and boisterous - no terribole twos for eg - he was great when ds2 as first born and he loves him to bits
now his behaviour is getting worse and worse - bedtimes are getting out of hand and he is becoming destructive
* sticker charts - positive reinforcement etc
* 'time out'
* clear expectations etc - preparing him in advance fr changes
* keeping routinr as stable as possible
* special time with me or dh
popsycal, big hugs. I'm not sure if I can offer anything more than the measures you say you've already tried, but I found exactly the same with ds1 and only now (ds2 is nearly one) do I find he's almost back to his old cheerful and helpful self.
I do find myself getting very annoyed with him and sometimes realise I'm making things worse by making such a big deal about relatively small stuff, like who picks up his socks off the floor! So I try to reserve 'time outs' for really important things he knows he shouldn't do (like hitting any one of us) and really focus on the positives. For a while we gave him stars - not in a chart, just for anything he did well. It made him feel far better about himself and helped me to remember to praise him rather than telling him off all the time.
He even gave us stars sometimes which was really lovely.
And I can't remember how old your little one is, but ds2 started nursery at 6 months and we have one afternoon when I take ds1 to football on his own. We both love it and he's usually really chatty so I get to hear what's going on in his 'world'!
other mumsnetters may have some better suggestions, if so I'm all ears!
I didn't mean to say anything he did 'well' for the stars, just anything that I thought was good or nice. And I remember he used to be very proud of going to nursery with stars on his top because the staff would ask why he had them and he or I could tell them that he'd walked to nursery nicely, or tidied away his breakfast bowl, or whatever.