Why I put a live spread readout on my chart and what it stopped me doing
a small change that saved me a lot of silly entries was adding a spread indicator to the corner of the chart. It shows the current spread in pips, and I set it to change color when it's more than a certain multiple of what's normal for that pair.
Before I did this, I'd enter a trade without noticing the spread was wide. The setup looked right and the stop was in the right place, but I'd started in a hole. With the readout, I can see at a glance and I just don't enter if it's red.
I also noticed patterns I hadn't paid attention to. The spread jumps at certain times, like right at the session open, near rollover and in the first moments after news. It also tends to be wider on certain pairs at certain hours. Seeing it on the screen all day made it a part of my decision, not an afterthought.
If your platform doesn't have one built in, there are free ones for it, or you can look at the market watch window with the spread column. The point is that the spread should be visible when you click.
Why I put a live spread readout on my chart and what it stopped me doing
Re: Why I put a live spread readout on my chart and what it stopped me doing
How I decided what counts as normal for each pair. I watched the spread readout for a couple of weeks and wrote down what it showed during my usual trading hours on quiet moments. That became my baseline. I set the colour change to about one and a half times that number. It is not exact, but it catches the obvious cases where the spread has doubled or tripled, which are the ones that really hurt a scalp. You can tweak the multiple later once you have a feel for each pair.
It’s Fairman 
Re: Why I put a live spread readout on my chart and what it stopped me doing
Another thing the readout made obvious is how much the spread affects where my stop really is. If my stop is five pips away and the spread is one pip, that is a big chunk of the risk before price even moves. When I saw that clearly, I stopped taking setups that needed very tight stops during wider spread periods. The setup looked identical, but the real risk was quite different. Now I either wait for the spread to calm down or use a setup with a wider stop and a smaller size, so the cost is a smaller share of the trade.
It’s Fairman 