Training advice please.

Some people put their bikes on the lightest gear and spin like crazy to get some blood flowing to their legs.  Some people stand up on their bikes and stretch as they get close to the bike finish line.  Many people will do a lot of bricks so that they get used to that feeling so that when that feeling happens during a race ... it's a "whatever"(i.e., been there done that) attitude as opposed to a "holly s$hit what do I do" attitude.  I think that any combination of those three will  help you a bit.

Other than races, I don't do any bricks.  For me personally, I just stand on my bike and stretch as I get closer to the bike finish line.   I still get that wigglie feeling but I now have that "whatever" been there done that attitude.  Once you've done enough bricks or enough races you will get used to the feeling and understand that it will disappear after about 5 minutes of running.  It doesn't even bother me any more.