I ask for as many deviations as I need for whatever reason I think I need them and most of the time ATC will let me do what I want.
As far as what to do about the clouds... I don't have a simple answer to that because it's not a simple question. My most recent flight went through an area for ~80nm that was under a convective airmet with lots of big poofy clouds in my way. However, there had been been no mention of storms in any TAF or local weather. Digging deeper into the "forecast discussion" I'd read something along the lines of "isolated t-storms are possible but probability too low to put in TAF"(if you have foreflight when you're looking up TAF info there's a forecast discussion button where you can read a text description of what the meteorologist is thinking... you'll find info like that in there, it can be insightful). I'd watched the weather all day, noting it was mostly stationary. A few lines of storms did pop up but nowhere near my course, mostly there were only short lived little dark green-yellow dots only a few pixels in diameter. Actual conditions were scattered-broken and cruising along at 8,000 I was in/out of them. I would guess no more than 4,000' or so of height. I watched my ADS-B weather closely along the route as well as my stormscope. Popped in/out of some slightly bumpy to smooth clouds for about 30-40min and popped out into clear weather. Never saw any precipitation or activity on the stormscope. There was one little dot barely 2nm in diameter close to my route with some yellow/red that I was prepared to deviate for but it was gone by the time I got close. Not the first flight I've had like this, probably not the last and there was nothing exciting to it.
Now if I'd seen TAFs all along my route with predicted storms/showers or seen rapidly moving/developing cells that's a whole other situation. If there were big anvil shaped clouds so tall I could see them 50nm away that's another situation. You really want to not just take in all the available information but also check how it's changing- both the forecasts and the actual radar data to get an idea of what's going on and what's likely to happen. The more you watch it the more you start to get a feel for it.
Always be ready to just land somewhere if you have to. Nobody wants to be stuck at some po-dunk airport for a day waiting out weather but it happens. Also for the types of summer scattered storms we're talking about, you usually see them in the afternoon. So flying in the morning or waiting until evening are often good strategies to avoid them entirely
As far as what to do about the clouds... I don't have a simple answer to that because it's not a simple question. My most recent flight went through an area for ~80nm that was under a convective airmet with lots of big poofy clouds in my way. However, there had been been no mention of storms in any TAF or local weather. Digging deeper into the "forecast discussion" I'd read something along the lines of "isolated t-storms are possible but probability too low to put in TAF"(if you have foreflight when you're looking up TAF info there's a forecast discussion button where you can read a text description of what the meteorologist is thinking... you'll find info like that in there, it can be insightful). I'd watched the weather all day, noting it was mostly stationary. A few lines of storms did pop up but nowhere near my course, mostly there were only short lived little dark green-yellow dots only a few pixels in diameter. Actual conditions were scattered-broken and cruising along at 8,000 I was in/out of them. I would guess no more than 4,000' or so of height. I watched my ADS-B weather closely along the route as well as my stormscope. Popped in/out of some slightly bumpy to smooth clouds for about 30-40min and popped out into clear weather. Never saw any precipitation or activity on the stormscope. There was one little dot barely 2nm in diameter close to my route with some yellow/red that I was prepared to deviate for but it was gone by the time I got close. Not the first flight I've had like this, probably not the last and there was nothing exciting to it.
Now if I'd seen TAFs all along my route with predicted storms/showers or seen rapidly moving/developing cells that's a whole other situation. If there were big anvil shaped clouds so tall I could see them 50nm away that's another situation. You really want to not just take in all the available information but also check how it's changing- both the forecasts and the actual radar data to get an idea of what's going on and what's likely to happen. The more you watch it the more you start to get a feel for it.
Always be ready to just land somewhere if you have to. Nobody wants to be stuck at some po-dunk airport for a day waiting out weather but it happens. Also for the types of summer scattered storms we're talking about, you usually see them in the afternoon. So flying in the morning or waiting until evening are often good strategies to avoid them entirely