You don't , you level in expert to 275, then switch to master & how the games built now running master at 275 (it's 300) is much easier than doing expert at 280. Sounds backwards but 1 tier is training you to do harder things without realising & when you switch you're already a better player. Trust the game to learn you & lead you.

Sorry, I'm a bit lame at game mechanics...what do I do? I'm 225 now, do I stick to expert until 275 you say? Then change to master? Sorry if I sound stupid, but I've never watched any videos on the mechanics, I just enjoy shooting aliens 😂

I've played LOTS & was confused too don't worry. So each tier the enemies are locked to the base number, so expert 200, master 300, GM 400, when you add the negative modifiers it adds to the enemy's base power in 10s & 20s making it harder for you but as you level up you catch up & it gets easier for a bit until you need to add more modifiers. Always use the auto rifle Ahab char, it's seasonal & solar, you want the perks subsistence & burning ambition. Primary try to get a mint retrograde rocket pulse from pinnacle playlist - you can play these at 10 power just to get 1 when it's featured & you melt everything, I did whisper. Heavy use the new fusion or sword. Always have the new armours equipped, if you've 7-8 new items you get extra score towards your grade & level faster. Modifiers, always choose in the middle one no starting ammo & locked loadouts, the top one choose whichever you're happy with, the banes one is easy if you avoid the shielding ones, they give extra score over 2 -10s or other -20 mods. You don't need any of the buff modifiers. Solo ops is the grind, caldera, creation, k1, are the fastest 3, try all 3 & see which you find easiest for you. Once you get routes down it's really easy, every run drops you upgrades, don't kill everything just what you need to, always do the extra challenge (ability kills, weapon kills etc) if you get precision kills just restart the run they take top long. Do the 7 training runs & when you've done 7 a new perk remembers your modifiers so you don't have to keep setting it up every run. Fire team ops is the worst for levelling, modifiers are set to b so no big drops & teammates can be really bad.

Someone that actually helps on the forum, great post!