I’m assuming a normal indoor fireplace with a metal grate to hold the logs, and logs sufficiently dried or seasoned (damp wood makes it very difficult).
Step 1: Clean out the ashes from the last fire if they’ve formed a thick layer.
Step 2: Make a bottom layer of crumpled paper.
Step 3. Make a middle layer of cardboard or thin wood kindling
Step 4. Make a top layer using a few logs. Put a log or two in the back as well.
Step 5. Light the paper on fire—one match should suffice.
That’s it. It should start burning on its own. If necesary add more kindling or cardboard. Sometimes you have to stuff additional paper into spaces at the bottom.
Step 6. Wait until the first logs have burned sufficiently to turn into red glowing coals. Now you can keep adding logs forever to sustain the fire. With a good bed of glowing coals the new logs should burn immediately with no additional kindling. Make sure there’s space between the logs for flames to spread between them.
I generally put two logs parallel to each other & set another log or 2 crosswise on top of these.
The ‘firestarter’ logs tend to stink up the house with a kerosene smell & run the risk of chimney fires.