Anal play has a reputation for being complicated or uncomfortable. It is neither, provided you go slowly and use enough lube. Here is the whole thing, in order.
Step 1: Understand the anatomy
There are two rings of muscle. The outer one you can relax consciously; the inner one you cannot — it relaxes on its own, given time and no pressure. That single fact explains almost every piece of advice that follows. Rushing does not work because the inner sphincter simply will not be hurried.
Worth knowing: the anus produces no natural lubrication. This is not something you can work around with arousal alone.
Step 2: Buy the right lube, and more than you think
Use a thick water-based lube, or silicone if you are not using silicone toys. Silicone lube lasts far longer and is excellent here, but it degrades silicone toys — pair it with glass, steel or ABS instead.
Reapply more often than feels necessary. Almost every bad first experience traces back to not enough lube.
Avoid anything numbing. Discomfort is information, and blocking it means you can injure yourself without noticing.
Step 3: Start much smaller than you expect
A finger, or a slim plug with a base no wider than about an inch across at its widest point. Beginners consistently buy too big. Something that feels almost disappointingly small is the correct starting size.
Non-negotiable: anything that goes in must have a flared base or a retrieval loop. The rectum is not a closed space, and items without a base can and do require hospital removal.
Step 4: Get relaxed first
A warm bath, an unhurried evening, and arousal before anything goes near the area. Tense muscles do not yield. If you are in a hurry, or anxious, or it is late and you are tired, another night will go better.
Step 5: Go in slowly, then wait
Apply lube generously to both the toy and yourself. Press gently and hold — do not push through resistance. Wait for the muscle to relax around the toy, which can take a minute or more, then continue. If it hurts sharply, stop. Pressure and fullness are normal; pain is not.
Step 6: Aftercare and cleanup
Wash toys with warm water and mild soap, or a dedicated toy cleaner, and dry them fully before storing. Never move a toy from anal to vaginal use without washing it thoroughly first — this is the fastest way to give yourself a nasty infection.
Mild soreness afterwards is common. Bleeding is not, and warrants a call to a doctor rather than a wait-and-see.
A note on douching
Optional, and easy to overdo. Plain warm water only, not soap, and not more than occasionally — frequent douching irritates the lining and strips it of the mucus that protects it. Many people skip it entirely and simply time things around their own routine.
If it is not working
Stop, and try again another day. Anal play responds badly to determination and well to patience. Most people who say it is not for them tried once, in a rush, without enough lube.