There have been lots of posts on the WW boards lately about things that people think matter to their weight loss, but don't, and I am really feeling the need to address two of these things:
1. Eating salt does not make you "gain" weight. Salt will make you retain water, which will show up on the scale, yes, but this is not fat and does not make you any more overweight. Water weight is just water, not fat. A litre of water weighs approximately 2 lbs, and if the amount of salt you're eating causing your body to retain this much water, then so be it, but at least you aren't holding on to 2 lbs of fat.
2. Whether or not you work out before a weigh in will only make a difference to that week, not to your overall weight loss (as is true for point 1). There are many factors to consider when you're working out - how much water are you drinking during the workout? How much water have you sweat off during your workout?, etc.
Now, having said my piece here, I will also say that I acknowledge how important it is psychologically to "see" a loss on the scale every week if you deserve one. I know we're all just trying not to sabotage ourselves right before weigh in. But just keep these things in mind EVERY weigh in - our body is going to do what it's going to do whether we like it or not. This is why we have plateaus and get frustrated. It doesn't mean we should give up!