Personally, a fibre shake that consists of half a cup of whole bran(all bran), 1tbsp of peanut butter, 1tbsp of coconut oil, 1tbsp of honey, half a cup of skim milk and 25ml of Dulcosoft(stool softener) in the morning keeps them soft and regular.
If I take it at 06:30, by 10:00 I have a very soft bm.
Snacks include 3 bran biscuits and a piece of fruit. Lunch I switched regular pasta to wholewheat with fish and at dinner I have some soup to get a little more veggies in. Sometimes I add beans when I feel the stool getting a little harder. Oh did I mention? LOADS OF WATER. I get 3 litres in a day. Stay away from red meat, processed foods and dairy products. Avoid heavy lifting or cardio. Basically anything strenuous that can work up a sweat. I had to stop working out completely,

If you drink coffee limit it to one shot in the morning just to stimulate your bm. This regime got me to a bearable position after having my fissure after 2 months. The first 2 were hell but these last 4 have been bearable after adopting this method. No bleeding anyomore and pain between a 2 and a 5 that usually lasts about 2 to 3 hours after a BM. Could be worse. I've read of some people on here that have constant spasms. I did the first 2 months and NEVER WANT THAT AGAIN. Unfortunately, my fissure was hemmis misdiagnosed and it went on too long. Ive been on GTN for 2 months and very little improvement so I am going to get LIS asap even if it is to save money on the 90 euros per month Im spending on meds.
If you catch it sooner you can fix it sooner. Dont let it drag on. If the pain gets worse and you get spasms, ask your GP to prescribe GTN and a Painkiller and keep those BMs soft as possible but not liquid. Most importantly. Listen to your body and dont panic.