1) use the encryption that your WAP supports - it'll be either WEP or WPA, WPA is the stronger.
2) MAC address filter - just allow your laptop MAC address.
3) Network address - change from the default (usually 192.168.0.0) to something else - like 192.168.101.0
4) name your wifi network something other than the default. Change the password of the WAP to something strong. If you can, change the admin account name to something else.
5) don't advertise the SSID of the network - assuming your WAP supports it.
6) DHCP scope - only use as many IP addresses as there are devices - in your case 2. So the network address is 192.168.101.0, the router is 192.168.101.1, the DHCP scope is 192.168.101.2 - 192.168.101.3. Create a reservation for you laptop's IP address.
7) for the truly paranoid, limit the IP addresses available on your network by changing the subnet mask to 255.255.248 - this would only allow 6 hosts on the network, including the router.