How do you keep your clothes clean and looking good? Seriously…

I feel like I destroy clothes and get them dirty/stained/damaged within weeks of buying something, even when I try to avoid doing work or dirty stuff in them. I live semi-off grid, have a dirty job and a pretty outdoors lifestyle so mud, coal, ash, engines are part of my every day life. I make an effort to wear scruffs for ‘work’ and keep my casual/nice stuff separate but it still gets wrecked and never comes up looking fresh. I buy everything except undies second hand for money/environment reasons but also seems a waste for me to get something new!

I feel so scruffy when I go into town or places surrounded by people in clean white trainers and crisp clean clothes. I have vvvv little storage so only have 2/3 good jumpers/hoodies on the go at a time. Any cleaning tips for getting out oily/coaly marks? Or advice on clothes that hide marks? Or outfits that aren’t dressy but won’t have me feeling like a total scruff :( I’m 35, petite, prefer casual/tomboy style jorts n tees, wide leg jeans etc