A car on a steep ramp has to be close to my truck on a beach. I often need all of my 30' tow strap to get my trailer out of shallow water. Either the surface isn't good near the shore or the trailer has to go way in to shallow waters. Get an automotive rated tow strap of a length that fits your circumstance at the ramp. I put a stainless handle on my tongue to strap to. Didn't want to cut or abrade the strap with an improvised attachment.
I have not had problems with tipping when pulling out unhooked trailers, but you better make sure the weight is properly balanced on the trailer! What I did find was I damaged the tongue jack wheel assembly. It isn't meant to take lateral stress and if it catches on the ramp or the beach you will tweak it. It is also possible to catch the tongue itself if it drags without the jack wheel support down (if the pull isn't constant and even to keep the tongue up). I bought a big caster wheel that I unbolt from the pictured position and install under the tongue for tow style retrieval. Kind of a hassle, but not as much as damaging my trailer tongue in Mexico was...
I didn't attach my tow strap before pushing out the trailer into this Estrero and it tried to roll off into the channel as the boat came off. I always use the tow strap as a control line when launching now, snorkeling for the trailer wasn't that bad...
Have fun!